Robotic catheter system and methods

ABSTRACT

The apparatus of one embodiment of the present invention is comprised of a flexible sheath instrument, a flexible guide instrument, and a tool. The flexible sheath instrument comprises a first instrument base removably coupleable to an instrument driver and defines a sheath instrument working lumen. The flexible guide instrument comprises a second instrument base removably coupleable to the instrument driver and is threaded through the sheath instrument working lumen. The guide instrument also defines a guide instrument working lumen. The tool is threaded through the guide instrument working lumen. For this embodiment of the apparatus, the sheath instrument and guide instrument are independently controllable relative to each other.

RELATED APPLICATION DATA

The present application is a continuation of pending patent applicationSer. No. 13/358,468, filed Jan. 25, 2012, which is a continuation ofpatent application Ser. No. 13/225,324, filed Sep. 2, 2011, now U.S.Pat. No. 8,257,303, which is a continuation of patent application Ser.No. 11/481,433, filed Jul. 3, 2006, now U.S. Pat. No. 8,052,636, whichclaims the benefit under 35 U.S.C. §119 to Provisional PatentApplication Nos. 60/695,947, filed Jul. 1, 2005, and 60/698,171, filedJul. 11, 2005. The foregoing applications and patents, along withapplication Ser. No. 11/073,363, filed Mar. 4, 2005, now U.S. Pat. No.7,972,298, are hereby incorporated herein by reference in theirentireties.

FIELD OF THE INVENTION

The invention relates generally to robotically controlled systems, suchas telerobotic surgical systems, and more particularly to a roboticcatheter system for performing minimally invasive diagnostic andtherapeutic procedures.

BACKGROUND OF THE INVENTION

Robotic interventional systems and devices are well suited for use inperforming minimally invasive medical procedures, as opposed toconventional techniques wherein the patient's body cavity is open topermit the surgeon's hands access to internal organs. For example, thereis a need for a highly controllable yet minimally sized system tofacilitate imaging, diagnosis, and treatment of tissues which may liedeep within a patient, and which may be accessed via naturally-occurringpathways such as blood vessels or other lumens, via surgically-createdwounds of minimized size, or both.

SUMMARY

In one embodiment of the disclosed inventions, a robotic medical systemincludes an elongate flexible sheath instrument comprising a sheathinstrument base and a sheath instrument lumen; an elongate flexibleguide instrument positioned in the sheath instrument lumen, the guideinstrument comprising a guide instrument base and a guide instrumentlumen; and an instrument driver having a sheath instrument interface anda guide instrument interface. The sheath instrument base may beoperatively and removably coupled to the sheath instrument interface,such that movement of the sheath instrument may be roboticallycontrolled by the instrument driver via the sheath instrument interface.Similarly, the guide instrument base may be operatively and removablycoupled to the guide instrument interface, such that movement of theguide instrument may be robotically controlled by the instrument drivervia the guide instrument interface. Preferably, the sheath instrumentinterface and guide instrument interface are independently translatablerelative to one another, such that the sheath instrument and guideinstrument are axially translatable relative to the sheath instrument.The system further includes an elongate working instrument positioned inthe guide instrument lumen, and having a proximal end coupled to anactuator that actuates the working instrument, the actuator beingoperatively and removably coupled to the instrument driver, such thatactuation of the working instrument may be robotically controlled by theinstrument driver via the actuator.

In another embodiment of the disclosed inventions, a robotic medicalsystem includes a master input device; an instrument driver; a flexiblesheath instrument comprising a sheath instrument base removably coupledto the instrument driver, the sheath instrument defining a sheathinstrument working lumen; a flexible guide instrument comprising a guideinstrument base removably coupled to the instrument driver, the guideinstrument positioned in the sheath instrument working lumen anddefining a guide instrument working lumen; and an elongate toolpositioned in the guide instrument lumen, the tool having a proximal endcoupled to an electo-mechanical tool actuator that is removably coupledto the instrument driver, wherein each of said sheath instrument, guideinstrument, and tool are independently controllable by the instrumentdriver in response to user commands entered through the master inputdevice.

Other and further embodiments will be apparent from the followingdetailed description when read in conjunction with the accompanyingfigures.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of illustratedembodiments of the invention, in which similar elements are referred toby common reference numerals, and in which:

FIG. 1 illustrates one embodiment of a robotic catheter system;

FIG. 2 illustrates another embodiment of a robotic catheter system;

FIG. 2.1 illustrates the operator control station of one embodiment;

FIG. 2.2 illustrates a reverse view of the operator control station ofFIG. 2.1;

FIG. 3 illustrates a closer view of a support assembly;

FIGS. 3.1-3.10B illustrate various components of the support assembly inaccordance to one embodiment;

FIG. 4 illustrates an isometric view of an instrument for use with oneembodiment of an instrument driver;

FIG. 5 illustrates an isometric view of two instruments;

FIG. 6 illustrates an exemplary mounting scheme;

FIGS. 7A-C illustrate draping configurations of one embodiment;

FIGS. 8A-B illustrate providing a sterile barrier in accordance to oneembodiment;

FIGS. 9-16 illustrate various embodiments of draping schemas;

FIG. 17 illustrates an isometric view of an instrument configures forinstrument steering;

FIG. 18 illustrates one embodiment of a catheter member;

FIG. 19 illustrates a cross sectional view of a catheter member;

FIG. 20 illustrates a cross sectional view of another embodiment of acatheter member;

FIG. 21 illustrates one embodiment of a catheter member having threecontrol element lumens;

FIGS. 22-24 illustrate embodiments of catheter members having anon-equidistant lumen configurations;

FIGS. 25-27 illustrate various embodiments of a metal spine;

FIG. 28 illustrates a cross sectional view of a metal spine;

FIGS. 29-30 illustrate a stress relief pattern for the spine of oneembodiment;

FIGS. 31-32 illustrate a polymeric spine of one embodiment;

FIGS. 33-34 illustrates one embodiment of a control element anchoringring;

FIGS. 35-49 illustrate various aspects of an instrument base inaccordance to one embodiment;

FIGS. 50-73 illustrate alternative embodiments of instruments;

FIGS. 74-85 illustrate various aspects of a sheath instrument inaccordance to one embodiment;

FIGS. 86-91 illustrate cross sectional views of various embodiments ofcoaxially coupled catheters;

FIGS. 92-94 illustrate the coupling of a seal and access port with thesheath catheter member of one embodiment;

FIGS. 95-96 illustrate internal features of one embodiment of aninstrument driver schematically;

FIGS. 97-103 illustrate various aspects of the instrument driver of oneembodiment;

FIGS. 103.1-103.11 illustrate various aspects of the instrument driverof another embodiment;

FIG. 104 illustrates one embodiment of an operator control station;

FIGS. 105A-B illustrate embodiments of master input devices;

FIGS. 106A-109B illustrate the kinematics for a catheter of oneembodiment;

FIGS. 110A-E illustrate catheter control in accordance to oneembodiment;

FIG. 111 illustrates one embodiment of a controls system flow;

FIGS. 112A-B illustrate examples of localization systems;

FIG. 113 illustrates the relationship between visualization andnavigation for one embodiment;

FIGS. 114-124 illustrate various aspects of a control schema for oneembodiment;

FIG. 125 illustrates the kinematics of one embodiment;

FIGS. 126-127 illustrate actuation coordinates for the kinematics ofexample;

FIG. 128 illustrates a block diagram of system with a master inputdevice;

FIG. 129 illustrates a sample flowchart of transforming a positionvector to a haptic signal;

FIG. 130 illustrates a block diagram of a system including hapticscapability;

FIGS. 131-136 illustrate tension control relationships for a splitcarriage design of one embodiment;

FIGS. 137-139 illustrate one method for synthesizing a tissue structuremodel;

FIGS. 140-148C illustrate various aspects of another embodiment foracquiring and compiling a tissue structure image;

FIGS. 149-150 illustrate multiple embodiments for acquiring athree-dimensional tissue structure model of a human left atrium;

FIGS. 151-157 illustrate various embodiments of contact sensing means;

FIGS. 158A-160D illustrate examples of interpreted master following;

FIGS. 161-172 illustrate a myocardial ablation procedure in accordancewith one embodiment of the present invention;

FIGS. 173A-D illustrate electrode configurations for variousembodiments;

FIGS. 174A-D illustrate tip options for other embodiments of workinginstruments;

FIG. 175 illustrates a system block diagram;

FIGS. 176A-B illustrate one embodiment for visualization of tissue byoverlaying images;

FIG. 177 illustrates a schematic for overlaying objects to the displayof one embodiment;

FIG. 178 illustrates one embodiment of a distributed systemarchitecture;

FIG. 179 illustrates the hardware and software interface of oneembodiment;

FIG. 180 illustrates the software interaction of one embodiment.

FIG. 181 illustrates one embodiment of a control console;

FIGS. 182-186D illustrate various touchscreens for the user interface ofone embodiment;

FIGS. 187A-187E illustrate several embodiments of instruments;

FIGS. 188A-B illustrate one embodiment of a sheath instrument baseassembly;

FIGS. 189A-C illustrate a guide instrument of one embodiment;

FIGS. 190A-C illustrate one embodiment of a dilator;

FIGS. 191A-C illustrate a needle of one embodiment;

FIGS. 192A-192Q illustrate exemplary embodiments of various toolsthreaded through the working lumen of a guide instrument;

FIG. 193 illustrates an embodiment of instrument and tool controlconfiguration for coaxially interfaced guide and sheath instruments;

FIGS. 194A, 194B, 194C, and 194D illustrate embodiments of sheath/guidecombinations coaxially positioned within larger instruments;

FIGS. 195A-195F illustrate one example of a system of coaxiallypositioned, steerable guide and sheath instruments being advanced into auterus during a transvaginal intervention procedure;

FIGS. 196A-196C illustrate an exemplary system and procedure to removean occlusion from a fallopian tube with a remotely actuated grasper toolpositioned in a guide instrument;

FIGS. 197A-197B illustrate an exemplary system and procedure to deployan expandable prosthesis in a fallopian tube with a balloon and a guideinstrument;

FIGS. 198A-198B illustrate an exemplary system and procedure to producelocalized scarring and occlusion of a fallopian tube with an ablationprobe and a guide instrument;

FIGS. 199A-199B illustrate an exemplary system and procedure to removetissue from the salpinx with a grasping and/or cautery tool positionedin a guide instrument;

FIGS. 200A-200B illustrate an exemplary system and procedure for a punchbiopsy of the ovary with a needle tool positioned in a steerable guideand sheath;

FIGS. 201A-201G illustrate an exemplary system and use of a roboticguide/sheath combination to perform a minimally invasive oophorectomyprocedure;

FIG. 202 illustrates one embodiment of a system and procedure wherein asheath instrument is advanced past the salpinx to facilitate furthersteerable advancement of a guide instrument and an associated tool intothe peritoneum;

FIGS. 203A-203C illustrates one embodiment of a system and procedurewherein a sheath instrument repositions a fallopian tube to allow acoaxial device to advance through the sheath into the peritoneum;

FIGS. 203.5A-203.5B illustrate an exemplary system and procedure whereinsteerable sheath and guide instruments are inserted into a patient'sinsufflated cavity through the umbilicus;

FIGS. 204A-204B illustrate an exemplary laparoscopic salpingectomysystem and procedure wherein a steerable endoscope is deployed throughan umbilicus port to facilitate viewing of a steerable instrumentassembly;

FIGS. 204.5A-204.5E illustrate an exemplary laparoscopic oophorectomysystem and procedure wherein part of the procedure is conducted throughvarious laparoscopic ports with one embodiment of a robotic catheterplatform;

FIGS. 205A-205B illustrate an exemplary laparoscopic ovarian punchbiopsy system and procedure with a needle tool inserted through asurgically created side port;

FIG. 206 illustrates one embodiment of a laparoscopic interventionalsystem and procedure that employs a sheath/guide/tool assembly and asteerable endoscopic instrument;

FIGS. 207A-207B illustrate one embodiment of a system and procedurewherein a steerable endoscopic instrument is used to keep the distal tipof an ablation tool in view during the locating and ablation ofendometrial lesions;

FIGS. 208A-208D illustrate one embodiment of a cecopexy system andprocedure wherein two instruments assemblies with needle grasping toolsare utilized laparoscopically through two access ports;

FIG. 208E illustrates another embodiment of a cecopexy system andprocedure wherein instrument assemblies are laparoscopically introducedfrom the side of the body opposite the cecum;

FIGS. 209A-209B illustrate an exemplary laparoscopic appendectomy systemand procedure that utilizes three robotic steerable instrumentassemblies;

FIGS. 209C-209D illustrate another embodiment of a laparoscopicappendectomy system and procedure wherein an endoscopic instrument ispositioned through the umbilicus and two other assemblies are introducedthrough side ports;

FIGS. 210A-210H illustrate one embodiment of a laparoscopicprostatectomy system and procedure utilizing robotic instrumentassemblies;

FIGS. 211A-211C illustrates one embodiment of a laparoscopichemicolectomy system and procedure utilizing steerable instrumentassemblies;

FIGS. 212A-212C illustrates one embodiment of a system and procedureusing steerable instrument assemblies to place a sling prosthesis aroundthe urethra;

FIGS. 213A-213B illustrates one embodiment of a system and procedureusing steerable instrument assemblies to install tensile suspensionelements to support the uterus;

FIGS. 214A-214C illustrates one embodiment of a laparoscopic Hellermyotomy system and procedure using a high precision instrument assembly;

FIGS. 214D-214E illustrates another embodiment of a laparoscopic Hellermyotomy system and procedure via a trans-thoracic approach;

FIGS. 215A-215C illustrate one embodiment of a laparoscopic Nissenfundoplication system and procedure using instrument assemblies;

FIGS. 216A-216C illustrate one embodiment of a laparoscopic system andprocedure to create a Roux-en Y anastomosis with instrument assemblies;

FIG. 216D illustrates one embodiment of a system and procedure forperforming a stomach reduction with a robotic catheter platform;

FIG. 216E illustrates another embodiment of a system and procedure forperforming a stomach reduction with a steerable robotic catheterplatform and an endolumenal fastening tool employed from inside thestomach;

FIG. 217A illustrates one embodiment of a system and procedure using asteerable instrument with a camera device to conduct a cystoscopy;

FIG. 217B illustrates one embodiment of a system and procedure using asteerable instrument with an ablation tool to perform ablation fromwithin the bladder;

FIGS. 217C-217D illustrates one embodiment of a system and proceduresteerably driving sheath and guide instruments to the kidney to handlekidney stones;

FIGS. 218A-218C illustrate one embodiment of a system and procedureusing a steerable catheter platform to access intraperitoneal structuresvia the bladder;

FIGS. 219A-219C illustrate one embodiment of a system and procedure toexpand the lower esophageal sphincter by positing an expandable balloonwith a steerable instrument assembly;

FIGS. 220A-220C illustrate one embodiment of a system and procedure toablate a lower esophageal sphincter by driving an ablation tool insidewith a steerable instrument assembly;

FIGS. 221A-221B illustrate one embodiment of a system and procedure forablating Ghrelin producing cells by driving an ablative probe toolcoupled to a steerable instrument assembly inside the stomach;

FIGS. 222A-222I illustrate embodiments of systems and procedures whereinan elongate steerable instrument assembly is used to navigate throughthe esophagus, stomach, and sphincter Oddi to access the pancreaticduct, common bile duct, cystic duct, gall bladder, hepatic ducts, andlive;

FIGS. 223A-223G illustrate one embodiment of a trans-gastriccholesectomy system and procedure utilizing a steerable instrument;

FIGS. 224A-224F illustrate one embodiment of a system and procedureusing a steerable instrument assembly to navigate the colon andintervening to biopsy, lyse, or remove tissue;

FIGS. 225A-225C illustrates one embodiment of a trans-bronchialintervention system and procedure wherein a steerable instrumentassembly is advanced down the bronchi to deploy an expandable stentstructure;

FIGS. 226A-226D illustrate another embodiment of a trans-bronchialintervention system and procedure wherein a steerable instrumentassembly is advanced down the bronchi to perform ablation;

FIGS. 227A-227C illustrate yet another embodiment of a trans-bronchialintervention system and procedure wherein a steerable instrumentassembly with an ablation tool is advanced down the bronchi to ablate tocause scarring;

FIGS. 228A-228D illustrate another embodiment of a trans-bronchialintervention system and procedure wherein a steerable instrumentassembly is used to position a side firing ultrasound array and a sideprotruding, retractable, needle electrode;

FIGS. 229A-229G illustrate various embodiment of Nasopharynxintervention systems and procedures wherein a steerable instrument isused to access and navigate the frontal, ethmoidal, or sphenoidal sinusvia the nasal passage;

FIGS. 230A-230E illustrate various embodiments of larynx interventionsystems and procedures using a flexible, steerable instrument assembly;

FIGS. 231A-231C illustrate embodiments of intervention systems andprocedures for the thyroid and parathyroid;

FIGS. 232A-232C illustrate embodiments of vascular intervention systemsand procedures using a steerable instrument platform to navigate theascending aorta;

FIGS. 233A-233E illustrate various embodiments of renal arteryintervention systems and procedures using a steerable instrumentassembly;

FIGS. 234A-234E illustrate one embodiment of a system and procedure forusing a downsized steerable instrument assembly to navigate up into thecarotid artery to perform a procedure; and

FIGS. 235A-235D illustrate one embodiment of a system and procedure forusing a downsized steerable instrument assembly to navigate past thecarotid arteries and up into the peripheral neurovascular to perform aprocedure.

DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS

Referring to FIG. 1, one embodiment of a robotic catheter system (32),includes an operator control station (2) located remotely from anoperating table (22), to which a instrument driver (16) and instrument(18) are coupled by a instrument driver mounting brace (20). Acommunication link (14) transfers signals between the operator controlstation (2) and instrument driver (16). The instrument driver mountingbrace (20) of the depicted embodiment is a relatively simple,arcuate-shaped structural member configured to position the instrumentdriver (16) above a patient (not shown) lying on the table (22).

In FIG. 2, another embodiment of a robotic catheter system is depicted,wherein the arcuate-shaped member (20) is replaced by a movablesupport-arm assembly (26). The support assembly (26) is configured tomovably support the instrument driver (16) above the operating table(22) in order to position the instrument driver (16) for convenientaccess into desired locations relative to a patient (not shown). Thesupport assembly (26) in FIG. 2 is also configured to lock theinstrument driver 16 into position once it is positioned.

Referring to FIG. 2.1, a view of another variation of an operatorcontrol station (2) is depicted having three displays (4), a touchscreenuser interface (5), and a control button console (8). The master inputdevice (12) depicted in the embodiment of FIG. 2.1 is depicted anddescribed in further detail in reference to FIG. 105B. Also depicted inthe embodiment of FIG. 2.1 is a device disabling switch (7) configuredto disable activity of the instrument temporarily. The cart (9) depictedin FIG. 2.1 is configured for easy movability within the operating roomor catheter lab, one advantage of which is location of the operatorcontrol station (2) away from radiation sources, thereby decreasingradiation dosage to the operator. FIG. 2.2 depicts a reverse view of theembodiment depicted in FIG. 2.1.

FIG. 3 provides a closer view of the support assembly (26) depicted inthe embodiment of FIG. 2.1. The support assembly (26) comprises a seriesof rigid links (36) coupled by electronically braked joints (34). Thejoints (34) allow motion of the links (36) when energized by a controlsystem (not shown), but otherwise prevent motion of the links.

The control system may be activated by a switch (e.g., a footswitch orthumb switch), or computer interface. In another embodiment, the rigidlinks (36) may be coupled by mechanically lockable joints, which may belocked and unlocked manually using, for example, locking pins, screws,or clamps. The rigid links (36) preferably comprise a light but strongmaterial, such as high-gage aluminum, shaped to withstand the stressesand strains associated with precisely maintaining a three-dimensionalposition of the approximately ten pound weight of a typical embodimentof the instrument driver (16) once the position of the link (36) isfixed.

FIGS. 3.1-3.10B depict another embodiment of the support assembly (26).Referring to FIGS. 3.1 and 3.2, in this embodiment, a mechanicaloperating table interface (1) includes a pair of clamp members (89) toremovably attach the support assembly (26) to the operating table (22)(shown in phantom outline). As explained in greater detail inconjunction with FIG. 3.3, the clamp members (89) include a lower clamptoe configured to pivot outwards for ease in engaging a rail (not shown)on an edge of the operating table (22).

The main body of the mechanical interface (1) is fixed to the housing ofa solenoid and brake unit (3). A proximal base of an arcuate, verticalextension member (11) is coupled to, and selectively rotatable about acentral axis of, the solenoid and brake unit (3). The vertical extensionmember (11) bends through an angle of approximately 90°, and has adistal end rotatably coupled, via a pan-rotate interface (13), to afirst end of a further proximal extension member (15). As explained ingreater detail in conjunction with FIG. 3.6, the pan-rotate interface(13) selectively allows extension member (15) to both rotate about anaxis of a distal extending shaft (55) (seen in FIG. 3.2), as well as panlaterally along an arc defined by lateral movement of the shaft (55)through a pan slot (111) defined by the housing (121) of the pan-rotateinterface (13) in a plane that is preferably parallel to a plane definedby the operating table.

A distal brake unit (19) is coupled to a sprocket comprising the secondend of extension member (15), the sprocket being rotatably coupled tothe housing of the extension member (15), as described in further detailbelow. The brake unit (19) is configured for selectively allowingrotation of an instrument driver support shaft (17) relative to thebrake unit (19), the support shaft (17) carrying a pivotable instrumentdriver mounting interface (21) for attaching the instrument driver (notshown). The support shaft (17) further includes a handle portion (23),which has a button (24) for electronically actuating the respectiveelectronic brake and solenoid in unit (3), as well as the distal brake(19), to thereby allow the afore-described motions of the variouscomponents of the support assembly (26). Cable holder brackets (113) areprovided along the exterior of the support shaft (17), pan-rotateinterface (13), and solenoid and brake unit (3), respectively, forattaching a power/control cable from the instrument driver (not shown).One a more control cables (not seen) also extend internally within thevarious components of the support assembly (26) from the distal endbutton (24) to the distal brake (19) and to the solenoid and brake unit(3).

The support assembly (26) is configured to facilitate easy positioningand repositioning of a remotely controlled instrument driver over theoperating table (22). When the button (24) on the handle portion (23) isdepressed, the respective electronic brakes and solenoid of the assembly(26) allow the respective interfaces to move freely relative to eachother, constrained only by the interface configurations, to allow forrepositioning of the handle (23) and associated instrument driversupport shaft (17) relative to the operating table (22). When the button(24) is not depressed, the respective brakes prevent any furthermovement of the support shaft (17), wherein the support assembly (26) isconfigured to provide a high level of mechanical stability. In oneembodiment, upon activation of the solenoid and release of the brakes,the distal brake unit (19) is configured to allow an approximately 135degree range of motion about the rotational axis (125) of the brake unit(19), the pan-rotate interface (13) is configured to allow anapproximately 140 degree range of motion rotation about the rotationalaxis of the shaft (55) as well as approximately 110 degrees of panrotational motion through the plane defined by the pan slot (111), andthe vertical extension member (11) is configured to allow anapproximately 350 degree range of rotational motion relative to thesolenoid and brake unit (3), which is configured to be coupled to anoperating table.

As shown in FIG. 3.3, the mounting clamps (89) each generally comprise afixed body portion (33) having a mating surface (101), and upper andlower clamp toe portions (115, 99) configured for attachably coupling toa rail (not shown) disposed on an edge of the operating table (22). Thelower clamp toe portion (99) is preferably fastened to the swingingclamp body portion (29), with a threaded locking member (25) used totighten/loosen the lower clamp toe portion (99) against the rail tosecure/release the clamp (89) thereto or therefrom. For ease in loadingthe assembly (26) onto an operating table rail, the mating surface (101)of the fixed clamp body portion (33) is indented to seat a fulcrum rod(27) that rides against a side of the rail, and the swinging clamp bodyportions (29) of the clamps (89) may be individually pivoted (95) aboutthe pin member (31) to rotate away from the operating table rail (notshown) to facilitate extending the upper clamp toe member (115) onto therail with easy access to the mating surface (101). In the depictedembodiment, the swinging clamp toe bodies (29) are spring (97) biased torotate (95) in this manner until the mating surface (101) has beenpositioned against the operating table rail (not shown), subsequent towhich the swinging clamp toe bodies (29) may be manually rotated aboutthe pin (31) and wound into position interfacing with the operatingtable rail (not shown) with the threaded locking member (25), asdepicted in FIG. 3.3.

Referring to FIG. 3.4, the solenoid and brake unit (3) comprises anouter housing (103) and an inner member (45) that is rotatably mountedwithin the housing (103). The inner member (45) includes a distal facingsurface (117), configured to receive a proximal mounting interface (94)of the vertical extension member (11) (see FIG. 3.2). In this manner,the extension member (11) (see FIG. 3.2) is rotatable about alongitudinal axis (119) of the solenoid and brake unit (3). A brakeassembly (39) is biased to prevent rotation of member (45), and thus ofextension arm (11), unless electronically actuated to release the member(45). In FIG. 3.5, the brake (39) is depicted, along with a flex-diskinterface (49) and a clamp (47), which couples firmly to the rotatableframe member (45). The flex-disk interface (49) allows for some axialmovement between the clamp (47) and the brake (39), without significantrotational slop commonly associated with more conventional splineinterfaces. Thus, manual rotation of the vertical arm (11) about an axiswhich may be substantially orthogonal to the operating table (22) (i.e.,for positioning an instrument driver (16) mounted on the support shaft(17) relative to a patient positioned on the operating table (22)) isselectively allowed by electronic activation of the brake (39) when thebutton (24) is depressed into the handle (23).

Referring back to FIG. 3.4, a top end of the solenoid and brake unit (3)includes a plunger (41), that is biased by a set of helical springs (43)to push away from the housing (103) of the solenoid and brake unit (3),into an interior bore of the extension member (11). When a solenoid (35)located in a lower portion of the housing (103) is electronicallyactivated, it pulls a pull-rod (37), which in turn pulls the plunger(41), in a compressive direction against the springs (43), toward thehousing (103) of the solenoid and brake unit (3).

As shown in FIG. 3.6, the vertical extension member (11) has a hollowinterior to accommodate an arcuate lever (57) configured to compress andlock into place the pan-rotate interface (13) when rotatedcounterclockwise about a pivot pin (61) within, and relative to, thevertical extension member (11) as the plunger (41) (see FIG. 3.4) ispushed upward away from the housing (103) (see FIG. 3.4) by the spring(43) load. With the plunger (41) pushed upward, the ball (53) is placedinto compression between the toe (130) of the arcuate lever (57) and acontoured surface (131) coupled to the base of the pan-rotate interface(13) housing (121). The ball (53), contoured surface (131) and bearings(63) mounted upon the shaft (55) preferably are configured to placesubstantially all of the applied compressive load upon the ball (53) andnot the bearings (63). When the plunger (41) is pulled downward by theactivated solenoid (35), the load previously applied by the plunger (41)to the wheelset (59) at the end of the arcuate lever (57) is releasedand gravity pulls the arcuate lever (57) into clockwise rotation aboutthe pivot pin (61), thus substantially releasing the compressive loadsthat lock into the place the pan-rotate interface (13) and allowingpanning and rotation of the shaft (55). The pan-rotate interface (13)includes a ball (53) and shaft (55) construct (collectively indicatedwith reference (51)), that, in one embodiment, is configured to providea 15:1 leverage ratio for loads applied by the plunger (41) at a wheelset (59) housed in the extension member (11) and coupled to the proximalend of the arcuate lever (57).

Referring to FIG. 3.7, the ball/shaft interface (51) comprises bearings(63) to facilitate stable panning rotation, as well as rotation of anassociated structure about the longitudinal axis of the shaft (55). Theball (53) preferably is greased to facilitate smooth panning androtation when not compressibly locked into position. The bearingsfacilitate lateral panning of the shaft member (55) about a plane formedby the pan-rotate interface (13), which causes the bearings (63) torotate on a planar annulus about the center of the ball (53). The resultis constrained motion in two different degrees of freedom: lateralpanning as per the planar annulus and bearing interface, and rotationabout the axis of the shaft (55). The bias force of the springs (43) onthe plunger (41) extending from the solenoid housing (103) normally lockthe ball/shaft interface (51) into place, preventing either panning orrotation motion at the interface. Electronic activation of the solenoidwithdraws the pull-rod and, by extension, plunger (41) away from thewheel set (59), thereby unloading the significant compressive forcesthat otherwise keep the ball (53) locked into place, allowing forpanning/rotation.

Referring also back to FIG. 3.2, the shaft (55) protrudes through ahorizontal pan slot (111) located in a distal face (123) of the housing(121) covering the pan-rotate interface (13). The pan slot (111)constrains the horizontal panning motion of the shaft (55), and byextension, the proximal extension member (15) in a plane that may besubstantially parallel to the operating table within the range of motiondefined by the boundaries of the slot (111).

Referring to FIG. 3.8, the shaft (55) is coupled to a proximal sprocket(75) of the horizontal extension member (15) using a conventionalinterference fit, such as a “number 3 Morse taper.” The proximalsprocket (75) is coupled to a distal sprocket (74) by a timing chain(73), so that rotation of the shaft (55) correspondingly rotates bothsprockets (74, 75), preferably with a 1:1 ratio of rotational movement,resulting in the same rotational displacement at each of the sprockets.Rotational movement of the proximal sprocket (75), caused by fixing therelative rotational position of the proximal sprocket (75) relative tothe distal face 123 of the pan rotate interface (13) housing (121) witha key member (105) fitted into key slots (77, 109) defined by the distalsprocket (74) and pan rotate interface (13) housing (121), causesrotation of a pin (65), which in turn causes tension via a linkage (67),proximal linkage base (71), and distal linkage base (69), respectively,to a set of gas tension springs (79) configured to constrain therotational motion of the sprockets (74, 75), and thus, of the shaft(55). The position (107) of the key member (105) is depicted in FIG.3.2. Given this configuration, with the solenoid (35) activated and thepan-rotate interface (13) free to move, the timing chain (73) andsprocket (74, 75) configuration within the horizontal extension member(15) is configured to maintain the relative planar positioning of themost distal hardware of the system relative to the plane of theoperating table. This is important because a robotic catheter driver(not shown; see FIGS. 3.10A-B, for example) may be mounted upon theinstrument driver interface (21) and pulled around by the handle (23),with the solenoid activated and the brakes released, to rotate about therotational axis (125) of the distal brake unit (19), to rotate about theaxis (119) of the rotatable frame member (45) within the solenoid andbrake unit housing (3), to rotate and pan about the pan-rotate interface(13) via connectivity of the horizontal extension member (15), allsimultaneously, without substantially changing the planar orientation ofthe instrument driver interface (21) relative to the plane of theoperating table (not shown). In other words, the axis of rotation (125)of the proximal extension (127) of the instrument driver support shaft(17) may be configured to always be oriented perpendicular to the planeof the operating table, by virtue of the timing chain and sprocketinterfacing of the extension member (15). When electronically activated,the brake unit (19) allows rotational movement of the support shaft (17)about an axis of the proximal extension (127). When the brake is notelectronically activated, such rotational movement of the support shaft(17) is prevented.

Referring to FIGS. 3.9A-B, the instrument driver support shaft (17)comprises an instrument driver mounting interface (21), and a biasingspring (80) configured to at least partially counterbalance thecantilevered load upon the instrument driver interface (21) caused bythe weight of an instrument driver mounted upon it. The biasing spring(80) preferably is covered by a spring housing (85). A lead screw (81)is provided and configured to change the pitch of the instrument driverinterface (21) relative to the support shaft (17) when a knob (83) isrotated.

Referring to FIGS. 3.10A-B, an instrument driver (16) fitted with acover (129) is depicted mounted to the instrument driver interface (21).The cover (129) is configured to provide an additional barrier betweenthe instrument driver which is covers and draping, liquids, vapors, andother substances that may be encountered during a procedure. Preferablythe cover (129) comprises a polymer or metal material and is made withprocesses such as stereolithography, injection molding, or machiningPreferably the cover (129) may be snapped or fastened into place aroundthe instrument driver with simple recessed screws, bolts, or otherfasteners. Similar covers may be configured to cover instrument bases.As depicted in FIGS. 3.10A-B, the cantilevered mass of the coveredinstrument driver (16) creates a moment. Torsional loads associated withsuch moment are counteracted by the spring (not shown in FIGS.3.10A-B—see biasing spring (80) of FIG. 3.9A) housed within the housing(85). This counteraction is configured to prevent binding of the knob(83) actuated lead screw (81) pitch control of the instrument driverinterface (21).

In summary, a support assembly (26), or support structure, is configuredto allow for easy repositioning of an instrument driver or other devicerelative to an operating table when an actuation button is depressed,thereby activating a solenoid and releasing two electronic brakes. Theposition of an instrument driver then may be easily fine-tuned, forexample, or modified quickly and substantially to remove the instrumentdriver from the immediate area of a patient on an operating table forquick medical intervention with broad physical access. Constraints limitthe movement of the instrument driver relative to the operatingtable—i.e., a pan-rotate interface (13), a horizontal extension member(15) with a rotational position maintaining timing chain (73) fordistally-coupled structures, and brake-lockable rotations about two axesof rotation (125, 119) which may be parallel and both perpendicularrelative to the plane of the operating table—to provide desirablemechanics. When an actuation button is not depressed and the structuresare substantially locked into position relative to each other, with theexception of manually-activated lead screw pitch adjustment of aninstrument driver interface (21), the support assembly (26) isconfigured to provide a robust structural platform upon which aninstrument driver or other device may be positioned relative to anoperating table.

FIGS. 4 and 5 depict isometric views of respective embodiments ofinstruments configured for use with an embodiment of the instrumentdriver (16), such as that depicted in FIGS. 1-3. FIG. 4 depicts aninstrument (18) embodiment without an associated coaxial sheath coupledat its midsection. FIG. 5 depicts a set of two instruments (28),combining an embodiment like that of FIG. 4 with a coaxially coupled andindependently controllable sheath instrument (30). To distinguish thenon-sheath instrument (18) from the sheath instrument (30) in thecontext of this disclosure, the “non-sheath” instrument may also betermed the “guide” instrument (18).

Referring to FIG. 6, a set of instruments (28), such as those in FIG. 5,is depicted adjacent an instrument driver (16) to illustrate anexemplary mounting scheme. The sheath instrument (30) may be coupled tothe depicted instrument driver (16) at a sheath instrument interfacesurface (38) having two mounting pins (42) and one interface socket (44)by sliding the sheath instrument base (46) over the pins (42).Similarly, and preferably simultaneously, the guide instrument base (48)may be positioned upon the guide instrument interface surface (40) byaligning the two mounting pins (42) with alignment holes in the guideinstrument base (48). As will be appreciated, further steps may berequired to lock the instruments (18, 30) into place upon the instrumentdriver (16).

In one embodiment, the instruments (18, 30) are provided for a medicalprocedure in sterile packaging, while the instrument driver (16) is notnecessarily sterile. In accordance with conventional sterile medicalprocedure, the non-sterile instrument driver (16) must be isolated fromthe patient by a sterile barrier of some type. Referring to FIGS. 7A-7C,a drape (50) comprising conventional surgical draping material may befolded into a configuration (52) to enable gloved hands of a person (notshown) to slide the drape (50) over the instrument driver (16), from oneend to the other without contamination of the sterile side of the drape(50). The drape (50) is then unrolled around the instrument driver (16),as shown in FIGS. 7B-7C.

Referring to FIGS. 8A and 8B, the interfacing between instrument driver(16) and instrument bases (46, 48) utilizing alignment pins (42) isdepicted to further illustrate the issues associated with providing asterile barrier between the instruments and driver. In the illustratedembodiment(s), wherein the instrument is a set of two instrumentscomprising both a sheath instrument (30) and a guide instrument (18),the draping is preferably configured to accommodate relative motion (56)between the two instrument bases (46, 48). Further, the fit between theinstrument bases (46, 48) and pertinent alignment pins (42) preferablyis not loose and does not allow for relative motion. Similarly, theinterface between axels (54) extending from the instruments and sockets(44) comprising the instrument driver (16) preferably is a precisioninterface.

Referring to FIGS. 9-16, various embodiments of suitable draping schemasare depicted. As shown in FIG. 9, a perforated drape (58) may beutilized, wherein perforations (68) are sized to fit the alignment pins(42) and interface sockets (44). The perforated drape (58), preferablymade from conventional draping materials, is simply alignedappropriately and pulled down upon the instrument driver (16).

Referring to FIG. 10, a perforated drape with socks (60) may also beutilized. The depicted drape (60) has perforations (68) for theunderlying interface sockets (44), but has socks (70), also formed fromconventional draping material, which are sized to encapsulate themounting pins (42) of the instrument driver (16).

Referring to FIG. 11, the depicted drape (62) may comprise “socks” (70)to engage the mounting pins (42), as with the drape in FIG. 10, but alsohave integrated plastic sleeves (64) rotatably coupled to thesurrounding conventional drape material. The integrated plastic sleeves(64) are preferably precisely sized to engage both the interface sockets(44) of the instrument driver (16) and the axels (not shown) of aninstrument. The sleeves (64) are preferably constructed of asterilizable, semi-rigid plastic material, such as polypropylene orpolyethylene, which has a relatively low coefficient of friction ascompared with conventional drape material. To decrease rotationalfriction between the integrated plastic sleeves (64) and the surroundingdrape material, perforations in the drape material through which thesleeves (64) are to be placed may be circumferentially lined withplastic collars (not shown), comprising a material having a lowcoefficient of friction relative to that of the integrated plasticsleeves (64).

Referring to FIG. 12, an embodiment similar to that of FIG. 11 isdepicted, with the exception that removable plastic sleeves (66) are notintegrated into the drape, as delivered and unwrapped. Instead, thedrape (60) may be delivered with perforations (68), circumferentiallylined in one embodiment with plastic collars (not shown), positioned forconvenient drop-in positioning of the sleeves (66). FIG. 13 is a closeup view of a plastic sleeve (66) suitable, for example, in theembodiment of FIG. 12. The sleeve (66) may also be integrated into theembodiment depicted in FIG. 11. FIG. 14 illustrates that the inside ofthe sleeve (66) may be fitted to engage an axle (54) extending down froman instrument body.

Referring to FIG. 14.5, an alternative variation of a set of instruments(28) is depicted, wherein all of the parts with the exception of screws(91) and an axle (93) are comprised of polymeric materials such aspolycarbonate or Delrin. As depicted in FIG. 14.5, each axle (93) formsa spline interface with the associated control elements pulley whichcarries an associated tension element.

Referring to FIG. 15, another draping embodiment is depicted, whereintwo semi-rigid covers or plates (72) are incorporated into a largerpiece of conventional draping material. The covers (72) are configuredto snap into position upon the sheath instrument interface surface (38)and guide instrument interface surface (40), fit over the mounting pins(42), and provide relatively high-tolerance access to the underlyinginterface sockets (44), with pre-drilled holes (76) fitted for thepertinent drive axle structures (not shown). Due to the anticipatedrelative motion between the two instrument interfaces, as previouslydescribed with reference to FIGS. 8A and 8B, it may be preferable tohave elastic draping material or extra draping material bunched orbellowed in between the two interfaces, as shown in FIG. 15, andsimilarly applicable to the embodiments of FIGS. 9-14.

Referring to FIG. 16, another semi-rigid covering embodiment comprises asemi-rigid covering for the entire local surface of the instrumentdriver (16), without conventional draping in between semi-rigidsub-pieces. To accommodate relative motion, high tolerance overlapsections (78) are provided with sufficient overlap to allow relativemotion without friction binding, as well as gapping of sufficienttightness that the sterility of the barrier remains intact. Thesemi-rigid covers of the embodiments of FIGS. 15 and 16 may be molded ormachined from polymeric materials, such as polycarbonate, which areinexpensive, sterilizable, somewhat flexible for manual snap-oninstallation, and fairly translucent to facilitate installation andtroubleshooting.

FIG. 17 is an isometric view of one embodiment of an instrument (18)configured for instrument steering via independent control of fourcatheter control elements, or four tension elements, such as cablescomprising materials, e.g., stainless steel. The proximal portion (82)comprises a guide instrument base (48) and four axles (54) withassociated manual adjustment knobs (86). The middle (84) and distalportions (87) comprise a catheter member which extends into the guideinstrument base (48) forming part of the proximal portion (82).

Referring to FIG. 18, a catheter member (90) is depicted having controlelement apertures (92) through the proximal portion (88) of the cathetermember to accommodate control elements (not shown), such as tensioncables. The control elements may be disposed along the length of thecatheter member (90), and positioned to exit the catheter through theapertures (92) and into association with other structures comprising theproximal portion (82) of the instrument. The proximal (88) and middle(84) portions of the catheter member (90) are shown in a substantiallystraight configuration, which is preferred for controllability of themore flexible distal portion (87). Indeed, the proximal (88) and middle(84) portions are structurally reinforced and made from stiffermaterials to enhance torque transmission and insertability to the distalportion, while also providing enough cantilever bendability tofacilitate access to remote tissue locations, such as the chambers ofthe heart.

FIG. 19 is a cross sectional view of the catheter member (90) at eitherthe proximal (88) or middle (84) portion. At the center of the crosssectional construct is a central (or “working”) lumen (108), thegeometry of which is selected in accordance with the requisite medicalapplication. For example, in one embodiment it is desired to pass acommercially available ablation catheter having an outer diameter ofabout 7 French through the working lumen (108), in which case it ispreferable to have a working lumen in the range of 7 French in diameter.The catheter member (90) and the robotic catheter system (32) can besized up or down in accordance with the desired procedure and tools. Theproximal portion of the catheter member (90) may be reinforced with astiffening member such as a braiding layer (98) which is preferablyencapsulated on the outside by an outer layer (96) having at least onecontrol element lumen (102) to accommodate a control element, such as atension cable (not shown), and a low-friction inner layer (100) selectedto provide a low-friction surface over the inside of the braiding layer(98). Four extruded lumens (102) are provided in the illustratedembodiment to accommodate four respective control elements (not shown).

To prevent relative rotational motion between the catheter member (90)and other structures which may surround it, the profile of the outerlayer adjacent the control element lumens (102) may be increased. Thecross section of the embodiment of FIG. 19 has a relatively low surfaceprofile (104) adjacent the control element lumens (102), as comparedwith the cross section of the embodiment of FIG. 20, which is otherwisesimilar to that of FIG. 19. Indeed, within the same catheter member, itis preferable to have a more pronounced surface profile distally tointerface with surrounding structures and prevent “wind up”, ortorsional rotation, of the distal and middle portions of the cathetermember. With the braiding layer (98) in the middle (84) and proximal(82) portions of the instrument, “wind up” is not as significant anissue, and therefore it is less important to have a pronounced surfaceprofile to interface or “key” with other adjacent structures.

FIG. 21 depicts an embodiment having three control element lumens (102)disposed approximately equidistantly from each other about the perimeterof the catheter member (90) cross section. This embodiment illustratesby way of non-limiting example that the catheter member (90) need not belimited to configurations comprising four control element lumens or fourcontrol elements. By way of another example, FIG. 22 illustrates anon-equidistant, three-lumen (102) configuration, with two-lumen (102)and single lumen (102) variations shown in FIGS. 23 and 24,respectively.

To facilitate more dramatic bendability at the distal portion (87) ofthe catheter member (90), a reinforcing structure other than a braidinglayer may be preferred. By way of non-limiting example, FIGS. 25-27depict a metal spine (110) having a unique stress relief geometry cutinto its walls. FIG. 28 depicts a cross section of an embodiment of ametal spine (110) to illustrate that the working lumen may be continuedfrom the proximal (88) and middle (84) portions of the catheter memberinto the distal portion (87) through the center of the metal spine(110). Indeed, the metal spine preferably has similar inner and outerdiameter sizes as the braiding layer (98) in the more proximal portionsof the catheter member (90). Depending upon the metal utilized for themetal spine (110), very tight bend radius operation of the distalportion (87) of the catheter member (90) is possible, due in significantpart to such a highly bendable reinforcing structure and its associatedrepeated stress relief pattern. To further enhance the flexibility ofthe distal portion (87) of the catheter member (90), softer polymericmaterials may be utilized in the construct, such as a polyether blockamide (Pebax®) resin from Arkema Inc. of Philadelphia, Pa. For example,in one embodiment, the outer layer (96) in the proximal (88) and middle(84) portions of the catheter member (90) may preferably be comprised ofa 70 Shore D hardness (durometer hardness value) Pebax® resin, while thedistal portion (84) and outer layer (96) may preferably be comprised ofa 35 or 40 durometer Pebax® resin.

Referring to FIGS. 29 and 30, one embodiment of a stress relief patternis depicted in close-up view to illustrate that the pattern may beshifted by about ninety degrees with each longitudinal step along thespine (110) to maximize the homogeneity of stress concentration andbending behavior of the overall construct. To further enhance theflexibility of the metal spine, and clean up undesirable geometricdiscrepancies left behind after laser cutting, the metal spine may bechemically etched and electropolished before incorporation into thecatheter member (90). As shown in FIG. 30, chemical etching takes thepattern from the original laser cut positioning (114) to a revisedpositioning (112) with larger windows in the pattern. In thisembodiment, subsequent to chemical etching, the pattern forms a reliefangle with sides (116, 118) with an intersection (120) and includedangle (122). Preferred metal spine materials include, but are notlimited to, stainless steel and nitinol.

Referring to FIGS. 31 and 32, the distal reinforcing structure may alsocomprise a polymeric spine (124) similarly configured to homogeneouslybend due to a stress relief pattern comprising the tubular wall of thespine (124). In particular, due to the greater fracture toughness ofmany available polymeric materials, a more squared stress concentratingpattern may be repeated with polymer structures. Further, high-precisionstructures such as the depicted polymeric spine (124), may be formedusing injection molding and/or other techniques less inexpensive thanlaser cutting and etching. As will be apparent to those skilled in theart, many other distal spine structures for concentrating and relievingstress may also be utilized to provide the requisite tight bend radiusfunctionality distally within the catheter member (90) construct,including but not limited to coils and braids.

Referring to FIGS. 33 and 34, a control element anchoring ring (126) isdepicted having two anchoring lumens (128) for each incoming controlelement to be anchored at the distal tip of the catheter member (90).The anchoring ring (126) comprises the last rigid construct at thedistal tip of the catheter member (90), beyond which only a lowdurometer polymeric atraumatic distal tip (not shown) extends, as thelow friction liner (100) meets the outer layer (96) subsequent to thesetwo layers encapsulating the anchoring ring (126). The anchoring ring(126) is the “anchor” into which the relatively high-tension controlelements are fixedly inserted—and is therefore a key to the steerabilityand controllability of the catheter member (90) regardless of the numberof control elements pulling upon it. In one embodiment, tension wirecontrol elements (not shown) insert into the outermost of the anchoringlumens, then bend directly back into the innermost of the anchoringlumens, where they are soldered to the anchoring ring, which comprisemachined or gold plated stainless steel for solderability.

FIGS. 35-49 depict various aspects of an instrument base at the proximalportion (82) of an instrument (18) similar to that depicted in FIG. 17.Referring to FIG. 35A, a control element interface assembly (132) isdepicted, comprising an axle (54), a control element pulley (136), amanual adjustment knob (86), and a drive engagement knob (134). Themanual adjustment knob is configured to facilitate manual adjustment ofcontrol element tensions during setup of the instrument upon theinstrument driver. It is held in place against the axle (54) with aclamp screw (138), and houses a rotation range of motion limitation pin(140) which limits the range of motion of the axle subsequent to setupand tightening of the clamp screw. Referring to FIG. 35B, one embodimentof an axle (54) is depicted in isometric view without other hardwaremounted upon it. Referring to FIG. 36, an axle (54) is depicted with adrive engagement knob (134) mounted upon it. The drive engagement knob(134) may take a shape similar to a screw with a long threaded portionconfigured to extend through the axle to engage a tapered nut (142), asshown. Twisting of the drive engagement knob (134) causes the taperednut (142) to urge the teeth (144) of the axle outward (223), therebyengaging whatever structures surround the lower portion of the axle,including, but not limited to a instrument driver interface socket (44).

FIGS. 37 and 38 depict respective orthogonal views of one embodiment ofa control element pulley (136). The central hole (148) in the pulley(136) is sized for a press fit upon an axle, and the control elementtermination engagement slot (146) is configured to capture a controlelement terminator, such as a lead or steel cable terminator, that ispushed into the slot before a control element is wound around the pulley(136) during manufacture or rebuilding. Referring to FIG. 38, the pulley(136) preferably has a flanged shape (150) to facilitate winding andpositional maintenance of a control element.

As shown in FIG. 39, the top portion (152) of one embodiment of a guideinstrument base (48) comprises slots (154) to interface with therotation range of motion limitation pins (140), which may be housedwithin a manual adjustment knob (86). FIG. 40 depicts a top view of thetop portion (152). FIG. 41 depicts the same top portion (152), as viewedisometrically from underneath, to demonstrate how two pulleys may bemounted in related to the top portion (152) of the guide instrument base(48). The control element splay tracks (158) are employed to guidecontrol elements (not shown) from apertures in a catheter member intopulleys which may be positioned within the pulley geometryaccommodations (160) formed into the top portion (152) of the guideinstrument base (48). Also shown in the top portion (152) is a cathetermember geometry accommodation (162) and a seal geometry accommodation(164). FIG. 42 depicts an orthogonal view of the structures of FIG. 41to better illustrate the control element splay track (158) structurespositioned to guide control elements (not shown) away from a cathetermember and over to a pulley associated with the top portion (152) of theguide instrument base (48).

Referring to FIG. 43, a bottom portion (156) of one embodiment of aguide instrument base (48) is configured to interface with a top portion(152) such as that depicted in FIGS. 39-42. The bottom portion (156) hastwo additional pulley geometry accommodations (160) and associatedcontrol element splay tracks (158). The top (152) and bottom (156)portions of the guide instrument base (48) are “sandwiched” together tocapture the proximal portion (88) of a catheter member (90), andtherefore the bottom portion (156) also has a catheter member geometryaccommodation (162) and a seal geometry accommodation (164) formed intoit. FIG. 44 depicts an orthogonal view of the structures of FIG. 43 tobetter illustrate the control element splay track (158) structurespositioned to guide control elements (not shown) away from a cathetermember and to a pulley associated with the bottom portion (156) of theguide instrument base (48). FIG. 45 depicts an underside isometric viewof the same bottom portion (156) shown in FIGS. 43 and 44. The bottomsurface may comprise magnets (166) to facilitate mounting of theinstrument upon an instrument driver 16. The depicted embodiment alsohas mounting pin interface holes (168) formed through it to accommodatemounting pins from an instrument driver 16. Further, the bottom surfacepreferably has a generally asymmetric geometry to ensure that it willonly fit an underlying instrument driver snugly in one way. FIG. 46depicts an orthogonal view of the bottom portion (156) of the guideinstrument base (48) embodiment of FIG. 45.

FIG. 47 illustrates one embodiment of a partially assembled instrumentproximal end (82), including a top portion (152) and bottom portion(156) of an instrument base (48) interfaced together. The proximal end(82) houses four pulleys (not shown), a catheter member (90), and a seal(170), including and a purging port (172). Three manual adjustment knobs(86) are shown mounted to the guide instrument base (48) by axles (54),which are held in place by pulleys (not visible) mounted upon the axles(54). Rotational range of motion limitation pins (140) interface withthe manual adjustment knobs and slots (154) in the guide instrument base(48) top portion (152). One of the four manual adjustment knobs 86 hasbeen omitted from the illustration in FIG. 47 to better illustrate theinteraction between the motion limitation pin (140) and slot (154). FIG.48 shows the locations of the control element pulleys (136) and controlelement splay tracks (158) within this four-control element embodiment.Control elements (not shown) preferably comprise solid wires made frommaterials such as stainless steel, which are sized for the anticipatedloads and geometric parameters of the particular application. They maybe coated with materials such as a Teflon® fluoropolymer resin fromDuPont of Wilmington, Del. to reduce friction forces. FIG. 49illustrates a different isometric view of an instrument base similar tothe embodiment of FIG. 47 to better illustrate the seal (170) andpurging port (172) positioning, as well as the clamp screws (138) of themanual adjustment knobs (86). The seal (170) preferably comprises asilicon rubber seal configured to accommodate insertion of workingmembers or instruments, such as, e.g., relatively small profileguidewires (e.g., in the range of 0.035″ diameter), or relatively largerprofile catheters (e.g., of up to 7 French or even larger).

Referring to FIGS. 50-73, other embodiments of instruments are depictedhaving the respective capabilities to drive two, three, or four controlelements with less than four control element interface assemblies (132)as previously discussed. For ease in illustration, many of the samecomponents are utilized in these embodiments. As will be appreciated bythose skilled in the art, such component matching is by no meansrequired to accomplish the described functions, and many alternativearrangements are possible within the scope of the inventions disclosedherein.

FIGS. 50, 51, and 52 illustrate an instrument (174) having two controlelement interface assemblies (132) is depicted in three orthogonalviews. While this embodiment has only two control element interfaceassemblies, it is configured to drive four control elements and keepthem in tension through either pre-tensioning, or active tensioningthrough a slotted guide instrument base (188) to a tensioning mechanismin the instrument driver (16). FIG. 53 illustrates an instrument (174)similar to that in FIG. 52, but shown from a back or bottom sideorthogonal view. In particular, one side of the guide instrument base(188) includes slots (190) through which an instrument driver tensioningmechanism may keep control elements taut during operation of theinstrument (174). FIG. 54 is a reverse orthogonal view of the structurein FIG. 53, with one side of the guide instrument base and both controlelement interface assemblies removed (132) to show the slots (190) andfour control elements (192).

FIG. 55 illustrates an instrument (175) similar to that in FIGS. 53 and54, with the exception that the guide instrument base (194) does nothave slots—but rather has only fixed idler control element pathways(196) to align the cables with the sets of two pulleys (136) comprisingeach control element interface assembly (132). In this embodiment,tension may be maintained in the control elements (192), withpre-tensioning, or pre-stressing, to prevent control element slack. FIG.56 also illustrates an instrument (174) similar to that of FIGS. 53 and54, including slots to allow for active tensioning of the controlelements (192) from the underlying instrument driver. One of the controlelement interface assemblies (132) is shown intact, and one is shownpartially intact, with the axle (54) and drive engagement knob (134)depicted to show the control elements (192). A notable differencebetween the embodiment in FIG. 56 and that in FIG. 55 is the addition ofthe tensioning slots (190).

Referring to FIGS. 57 and 58, yet another instrument embodiment (176) isdepicted in isometric and side views, respectively, with this embodimenthaving two control element interface assemblies (132) to drive fourcontrol elements (192). As shown in the partial cutaway isometric viewof FIG. 59, and close up cutaway view of FIG. 60, this embodimentdiffers from the fixed idler embodiment of FIG. 55, or the slottedembodiment of FIG. 56, in that it has four spring-loaded idlers (198) toassist with tensioning each of the four control elements (192).Referring to FIG. 60, each of the control elements (192) passes througha spring loaded idler (198), which urges the control element (192) intotension by trying to rotate (200). This tensioning schema may be easiestto visualize in the orthogonal cutaway view of FIG. 61, wherein thespring loaded idlers (198) are depicted urging (200) the four controlelements (192) into tension. The wireframe orthogonal view of FIG. 62also shows the stacks of two pulleys (136) each on each control elementinterface assembly (132) to accommodate four control elements (192).

FIGS. 63 and 64 depict another instrument embodiment (178), this onehaving three control element interface assemblies (132) for threeindependent control elements (192). As best seen in FIG. 64, thisembodiment is similar to that of FIG. 47, for example, except that ithas one less control element and one less control element interfaceassembly (132). FIG. 65 depicts yet another guide instrument embodiment(180) coupled with a sheath instrument (30). In particular, instrument(180) has two control element interface assemblies (132) and two controlelements. As seen in FIG. 66, the guide instrument (180) of thisembodiment is not configured for slotted tensioning or spring-loadedtensioning. Instead, the control elements (192) of this embodiment maybe actively tensioned independently, and/or pre-tensioned, to facilitatemaintenance of tension for control purposes.

Referring to FIG. 67, yet another instrument embodiment (182) is showncoupled with a sheath instrument (30). Instrument (182) has a singlecontrol element interface assembly (132) and two control elements. Asseen in FIG. 68, this embodiment of the instrument (182) is also notconfigured for slotted tensioning or spring-loaded tensioning. Instead,the control elements (192) of this embodiment may be pre-tensioned andkept in position with the help of a fixed idler control element pathway(196) to facilitate maintenance of tension for control purposes. FIG. 69illustrates still another instrument embodiment (184), which is showncoupled with a sheath instrument (30). Instrument (184) has a singlecontrol element interface assembly (132) and two control elements (192),with a spring-loaded idler (198) tensioning of the control elements(192), as shown in FIG. 70. As with the aforementioned spring-loadedidler tensioning instrument embodiments, the spring-loaded idlers urge(200) the control elements (192) into tension to facilitate control.

FIG. 71 illustrates a still further instrument embodiment (186), whichis shown coupled with a sheath instrument (30). Instrument (186) has asingle control element interface assembly (132) and two control elements(192), with a single-slotted guide instrument base, as shown in FIG. 72.As with the aforementioned slotted-tensioning instrument embodiments,the slot (190) facilitates tensioning of the control elements (192) froma mechanism in the instrument driver below (16). FIG. 73 depicts theembodiment of FIG. 72, with both portions of the slotted guideinstrument base (202) intact. Depending upon the amount of tensioningdeflection within the slot (190), it may be desirable to remove therotational range of motion limitation pin (not shown) from the manualadjustment knob (not shown) to prevent impingement of the pin, knob, andinstrument base (202), as the control element interface assembly (132)is moved in the slot (190) relative to the rest of the instrument base(202).

Referring to FIGS. 74-93, elements of a sheath instrument embodimentwill now be described. Again, for ease in illustration, many of the samecomponents from the previously described instrument embodiments isutilized in these further embodiments, although such component matchingis by no means required to accomplish the described functions.

FIG. 74 depicts a guide instrument (18) shown coupled coaxially with asheath instrument (30), together forming what has been described as aset of instruments (28). In FIGS. 75 and 76, the sheath instrument (30)is depicted without the guide instrument of FIG. 74. In FIG. 76, thesheath instrument (30) of one embodiment is depicted having one controlelement interface assembly (132), and preferably only one controlelement (not shown). From a functional perspective, in most embodimentsthe sheath instrument need not be as drivable or controllable as theassociated guide instrument, because the sheath instrument is generallyused to contribute to the remote tissue access schema by providing aconduit for the guide instrument, and to point the guide in generallythe right direction. Such movement is controlled by rolling the sheathrelative to the patient, bending the sheath in one or more directionswith a control element, and inserting the sheath into the patient. Theseal (204) is generally larger than the seal on the guide instrument dueto the larger diameters of elongate members that may be inserted intothe sheath instrument (30) as part of a medical procedure. Adjacent theseal (204) is an access port (206), which may be utilized to purge theinstrument, or circulate fluids or instruments. The bottom (210) and top(212) portions of the sheath instrument base (46) are preferablysandwiched to house portions of the control element interface assembly(132), such as the single pulley (136) in this embodiment, and theproximal portion of the sheath catheter member (208).

Referring to FIG. 77, the bottom portion (210) of one embodiment of asheath instrument base (46) is depicted showing two magnets (166)utilized to facilitate mounting against an instrument driver (16).Mounting pin interface holes (168) also assist in accurate interfacingwith an instrument driver (16). The opposite surface is formed with asheath catheter member geometry accommodation (214) to interface withthe sheath catheter (not shown). FIG. 78 shows this opposite surface ofthe bottom portion (210) in further detail, having a pulley geometryaccommodation (218), a seal geometry accommodation (216), and a sheathcatheter geometry accommodation (214). There is also a control elementsplay track (220) similar to those depicted in reference to theembodiments of the guide instrument. In FIG. 79, a bottom view of a topportion (212) of one embodiment of a sheath instrument base (46) isdepicted showing the sheath catheter geometry (214) and seal geometry(216) accommodations formed therein, and an axle interface hole (222)formed there through.

FIG. 80 illustrates yet another embodiment of the sheath catheter member(208) in a pre-bent formation, which may be desirable depending upon theanatomical issue pertinent to the medical procedure. The sheath cathetermember (208) preferably has a construction somewhat similar to that ofthe aforementioned guide catheter member embodiments, with notableexceptions. For one embodiment, the sheath catheter member (208)preferably does not have a flexible structural element disposed withinits distal end as it is not within the preferred functionality of thesheath instrument to have very tight radius bendability, particularlygiven the high bendability of the associated guide instrument.Preferably both the proximal (224) and distal (226) portions comprise alow-friction inner layer, a braiding layer, and an outer layer, asdescribed below with reference to FIG. 81. It is preferable to have morebending flexibility in the distal portion than in the proximal portion.This may be accomplished in one embodiment by selecting a outer layerpolymeric material for the distal portion (226) having approximatelyhalf the durometer of the polymeric material utilized for the outerlayer of the proximal portion (224). In the depicted embodiment, anatraumatic distal tip (228) comprising an extension of the low-frictioninner layer and outer layer extends slightly beyond the termination ofthe braiding layer by between about ¼ inch and ⅛ inch to prevent damageto tissues in various medical procedures.

FIG. 81 is a cross sectional view of a proximal or distal portion of asheath catheter member (208), similar to that shown in FIG. 80. Abraiding layer (230) is surrounded by an outer layer (232) preferablycomprising a polymer such as Pebax® with a durometer hardness valuebetween 30 to 80 Shore D hardness and an inner layer (234) preferablycomprising a low-friction polymeric material into which one or morelumens may be optionally extruded. The embodiment of FIG. 81 depicts onecontrol element lumen (236). The geometry of the inner layer (234) maybe configured to “key” or restrictively interface with a guide cathetermember outer geometry to prevent rotation of the guide catheter memberas discussed below with reference to FIGS. 85-91. The central lumen(238) of the sheath catheter preferably is sized to closely fit anassociated guide catheter member. FIG. 82 depicts an embodiment similarto that shown in FIG. 81, with the exception that this embodiment doesnot have a control element lumen. In some embodiments, it is preferablenot to have a steerable sheath catheter, but instead to have a straightor pre-bent sheath catheter, or no sheath catheter at all, surrounding aportion of the guide catheter.

Referring to FIGS. 83 and 84, an embodiment of a sheath catheter memberis depicted with an inner layer (234) configured to key with a3-control-element guide geometry, such as that depicted in FIG. 21. FIG.84 depicts a similar embodiment without a control element lumen (236).FIG. 85 depicts an non-keyed sheath without any control element lumensto illustrate that keying and steerable control is not necessary ordesired in some embodiments or procedures—particularly when morebendability of the sheath is desired. The embodiment of FIG. 85 isrelatively thin walled, and while it still comprises a braiding layer(230) surrounded by an outer layer (232) and an inner layer (234) ofpolymeric material, it is generally more easily bendable throughtortuous paths than are other more thick-walled embodiments. Further,without the keying geometry of the inner layer (234), the central lumen(238) is effectively larger.

FIGS. 86-91 illustrate cross sectional representations of variousembodiments of coaxially coupled guide catheter (90) and sheath catheter(208) combinations.

Referring to FIG. 86, a relatively low surface profile (104) guidecatheter (90) is disposed within sheath catheter (208) having fourcontrol element lumens (236). The fit between the two structures isfairly loose, and some relative rotational displacement is to beexpected if the guide catheter (90) is torqued significantly more thanthe sheath catheter (208). To help prevent such relative rotationaldisplacement, a higher profile guide catheter (90) geometry may beutilized, as shown in the embodiment of FIG. 87, in order to decreasethe freedom of movement between the two structures (90, 208) as they arebent through the pathways required by a medical procedure.

FIG. 88 depicts an embodiment similar to that in FIG. 87, but withoutthe control element lumens (236) in the sheath catheter member (208). Itmay be desirable to have control element lumens formed into the walls ofthe guide catheter or sheath catheter for reasons other than passingcontrol elements through such lumens. These lumens may also function asstress relief structures to increase bendability. The lumens may also beutilized to form preferred bending axes for the overall structure.Further, they may be utilized as working channels for flushing, drugdelivery, markers, sensors, illumination fibers, vision fibers, and thelike. It may be desirable to have a homogeneous patterning of controllumens across the cross section of a particular structure in order topromote homogeneous bending. For example, a sheath catheter with fourcontrol lumens, one of which is occupied by a control element intension, may bend more homogeneously than a sheath catheter with onlyone or two control lumens, one of which occupied by a control element.

Referring to FIG. 89, a relatively high surface profile (106) guidecatheter (90) is depicted within a non-keyed sheath catheter (208). Inthis embodiment, a 4-control-element guide catheter is disposed within apre-bent sheath instrument that is not remotely steerable. FIG. 90depicts a similar embodiment to that of FIG. 89 with the exception of alower surface profile (104) guide catheter (90) disposed within thenon-keyed sheath catheter (208). FIG. 91 depicts an example of keying toresist relative rotational displacement between a guide catheter (90)and a sheath catheter (208). Significant resistance to rotationaldisplacement is traded for higher degrees of overall system bendability,as will be apparent to those skilled in the art. As shown in FIG. 92, apreferably elastomeric seal (204) and access port (206) construct may befitted onto the sheath catheter member (208), prior to mounting withinthe confines of the sheath instrument base (46). FIG. 93 is a side viewof the sheath catheter member (208) coupled to the seal (204) and accessport (206). FIG. 94 is an end view of the seal (204).

FIGS. 95-103 depict various aspects of embodiments of an instrumentdriver configured for use with the above-described instrumentembodiments.

FIGS. 95 and 96 are simplified schematics that illustrate internalfeatures and functionalities of one embodiment of an instrument driver(16). In FIG. 95, a carriage (240) is slidably mounted upon a platform(246), which is slidably mounted to a base structure (248). The slidablemounting (250) at these interfaces may be accomplished withhigh-precision linear bearings. The depicted system has two cables (256,258) running through a plurality of pulleys (244) to accomplishmotorized, synchronized relative motion of the carriage (240) andplatform (246) along the slidable mounting interfaces (250). As will beapparent to those skilled in the art, as the motor (242) pulls on thecarriage displacement cable (256) with a tension force T, the carriage(240) feels a force of 2*T. Further, as the motor pulls the carriagedisplacement cable (256) by a displacement X, the carriage moves by X/2,and the platform moves by half that amount, or X/4, due to its“pulleyed” synchronization cable (258).

FIG. 96 illustrates a top view of a separate (but similar) systemconfigured to drive an instrument interface pulley (260) associated withan instrument interface socket (262) to produce both directions ofrotation independently from the position of the carriage (240), to whichit is coupled, along the linear pathway prescribed by the slidablemounting interfaces (250). With a mechanical schema similar to that inFIG. 95, as the motor (242) pulls a deflection X in the instrumentinterface cable (264), the same deflection is seen directly at theinstrument interface pulley (260), regardless of the position of thecarriage (240) relative to the motor (242), due to the synchronizingcable (266) positioning and termination (252).

Referring to FIGS. 97-103, systems similar to those depicted in FIGS. 95and 96 are incorporated into various embodiments of the instrumentdriver (16). In FIG. 97, an instrument driver (16) is depicted asinterfaced with a steerable guide instrument (18) and a steerable sheathinstrument (30). FIG. 98 depicts an embodiment of the instrument driver(16), in which the sheath instrument interface surface (38) remainsstationary, and employs a simple motor actuation in order for a sheathto be steered using an interfaced control element via a control elementinterface assembly (132). This may be accomplished with a simple cableloop about a sheath socket drive pulley (272) and a capstan pulley (notshown), which is fastened to a motor, similar to the two upper motors(242) (visible in FIG. 98). The drive motor for the sheath socket driveschema is hidden under the linear bearing interface assembly.

The drive schema for the four guide instrument interface sockets (270)is more complicated, due in part to the fact that they are coupled to acarriage (240) configured to move linearly along a linear bearinginterface (250) to provide for motor-driven insertion of a guideinstrument toward the patient relative to the instrument driver,hospital table, and sheath instrument. The cabling and motor schema thatmoves the carriage (240) along the linear bearing interface (250) is animplementation of the diagrammatic view depicted in FIG. 95. The cablingand motor schema that drives each of the four depicted guide instrumentinterface sockets is an implementation of the diagrammatic view depictedin FIG. 96. Therefore, in the embodiments of FIGS. 98-103, wherein fourseparate cable drive loops serve four separate guide instrumentinterface sockets (270), and wherein the carriage (240) has motorizedinsertion, there is achieved a functional equivalent of a system such asthat diagrammed in FIGS. 95 and 96, all fit into the same construct.Various conventional cable termination and routing techniques areutilized to accomplish a preferably high-density instrument driverstructure with the carriage (240) mounted forward of the motors for alower profile patient-side interface.

Still referring to FIG. 98, the instrument driver (16) is rotatablymounted to an instrument driver base (274), which is configured tointerface with an instrument driver mounting brace (not shown), such asthat depicted in FIG. 1, or a movable setup joint construct (not shown),such as that depicted in FIG. 2. Rotation between the instrument driverbase (274) and an instrument driver base plate (276) to which it iscoupled is facilitated by a heavy-duty flanged bearing structure (278).The flanged bearing structure (278) is configured to allow rotation ofthe body of the instrument driver (16) about an axis approximatelycoincident with the longitudinal axis of a guide instrument (not shown)when the guide instrument is mounted upon the instrument driver (16) ina neutral position. This rotation preferably is automated or powered bya roll motor (280) and a simple roll cable loop (286), which extendsaround portions of the instrument driver base plate and terminates asdepicted (282, 284). Alternatively, roll rotation may be manuallyactuated and locked into place with a conventional clamping mechanism.The roll motor (280) position is more easily visible in FIG. 99.

FIG. 100 illustrates another embodiment of an instrument driver,including a group of four motors (290). Each motor (290) has anassociated high-precision encoder (292) for controls purposes and beingconfigured to drive one of the four guide instrument interface sockets(270), at one end of the instrument driver (16). Another group of twomotors (one hidden, one visible—288) with encoders (292) are configuredto drive insertion of the carriage (240) and the sheath instrumentinterface socket (268).

Referring to FIG. 101, a further embodiment of an instrument driver isdepicted to show the position of the carriage (240) relative to thelinear bearing interfaces (250). Also shown is the interfacing of aportion of a instrument interface cable (264) as it bends around apulley (244) and completes part of its loop to an instrument interfacepulley (260) rotatably coupled to the carriage (240) and coupled to aguide instrument interface socket (270), around the instrument interfacepulley (260), and back to a motor capstan pulley (294). To facilitateadjustment and installation of such cable loops, and due to the factthat there is generally no requirement to have a loop operating for along period of time in one direction, thereby perhaps requiring a trueunterminated loop, two ends of a cut cable loop preferably areterminated at each capstan pulley (294).

The carriage (240) depicted in the embodiments of FIGS. 97-101 generallycomprises a structural box configured to house the instrument interfacesockets and associated instrument interface pulleys. Referring to FIGS.102A-B, a split carriage (296) is depicted, comprising a main carriagebody (304) similar to that of the non split carriage (240) depicted inprevious embodiments (240), and either one or two linearly movableportions (302), which are configured to slide relative to the maincarriage body (304) when driven along either forward or backwardrelative to the main carriage body by a gear (300) placed into one ofthe guide instrument interface sockets, the gear (300) configured tointerface with a rack (298) mounted upon the main carriage body (304)adjacent the gear (300). In an alternate embodiment, the carriage neednot be split on both sides, but may have one split side and onenon-split side. Further, while a carriage with four guide instrumentinterface sockets is suitable for driving a guide instrument withanywhere from one to four control element interface assemblies, theadditional hardware required for all four control element interfaceassemblies may be undesirable if a particular instrument simply needsone or two.

Referring to FIGS. 103.1-103.11, another variation of an instrumentdriver is depicted, comprising a variation of a split carriage design,such as that depicted in FIG. 102B. As opposed to the embodiment of FIG.102, wherein each instrument base interface is moved straight along aslot, or rotated, or both (independently), the embodiment of FIGS.103.1-103.11 provides rotation and/or arcuate slot motion by a “winged”split carriage design, wherein the tension member pulleys and axles maybe rotated about the axle axis, or moved along an arcuate pathway,independently.

Referring to FIG. 103.1, a winged split carriage instrument driver (135)is depicted coupled to a guide instrument (215) configured for thewinged split carriage with a specialized guide instrument base (141)having two arcuate slots (145) as opposed to the straight slots of otherembodiments, such as those described in reference to FIGS. 53, 54, and72, for example. One or more electronics boards (139) preferably arecoupled to the main housing structure (137) of the winged split carriageinstrument driver (135). The depicted assembly also comprises a sheathinstrument (30) movably threaded over at least a portion of the guideinstrument (215) and coupled to the sheath frame block (185) which iscoupled to the main housing structure (137) when the depicted assemblyis fully assembled.

Referring to FIG. 103.2, a guide instrument base (141) for oneembodiment of a winged instrument driver is depicted showing the arcuateslots (145) in greater detail, as well as a winged instrument driverguide instrument base top plate (143), which is configured to be fitteddown upon the proximal tubular portion of a guide instrument cathetermember (not shown) to maintain the relative positioning of the cathetermember (not shown) relative to the guide instrument base (141). Anunderside isometric view of the same structures depicted in FIG. 103.2is depicted in FIG. 103.3. In the depicted embodiment, a low-profilecontrol element interface assembly (147) is configured to rotate aboutthe longitudinal axis (219) of the interface assembly while alsoslidably translating through its associated arcuate slot (145). FIG.103.4 depicts an exploded view of the guide instrument base (141) ofFIG. 103.2. In FIG. 103.4, the guide instrument base top plate (143) andthe guide instrument base bottom plate (133) are shown separately.Furthermore, the arcuate slots (145) are shown defined in the bottomplate (133).

Referring to FIG. 103.5, a low-profile control element interfaceassembly (147) is shown in isometric view comprising a splined axle(157) coupled to a pulley flange (153), and also coupled to a set ofcontrol element pulleys (155) which are compressed between a low-profilemanual adjustment knob (151) and the pulley flange (153) with aretaining fastener (149), such as a screw. An exploded view of the samestructures is depicted in FIG. 103.6. Also shown in FIG. 103.6 is a pin(159) configured to prevent relative rotational displacement between thetwo control element pulleys (155) when the low-profile control elementinterface assembly (147) is assembled. The depicted embodiment oflow-profile control element interface assembly (147) may be utilizedwith any of the aforementioned instrument base and instrument driverassemblies, provided that the instrument interface sockets (44) are alsogeometrically matched for a splined interface between socket and axlefacilitating highly-efficient transfer of loads between the matchedsocket and axle. The low-profile control element interface assembly(147) preferably comprises polymers or metals which may be formed ormachined into very high precision subassemblies or parts which are lowin weight, high in hardness, and low in fracture toughness. In oneembodiment, each of the components of the low-profile control elementinterface assembly (147) comprises polycarbonate orultra-high-molecular-weight polyethylene.

Referring to FIG. 103.7, a winged split carriage assembly is depicted insemi-exploded view. The winged carriage base (173) is configured torotatably support two independently rotatable wing structures (221),each comprising a bottom portion (165) and a top portion (163). Afurther exploded view of the wing structures (221) and associatedmembers are depicted in FIG. 103.8. Rotatably coupled to the rotatablewing structures (221) is a set of control element pulleys (167) to whicha splined instrument interface socket (161) is coupled. The wingedcarriage base (173) is configured to slidably couple to a carriageinterface frame (not shown) with bearings (179). As shown in FIG. 103.9,slots (181) constrain the motion of the winged carriage base (173)relative to the carriage interface frame (191) to linear motion. Shaftsand bearings are utilized to rotatably couple the wing structures (221)to the winged carriage base and facilitate rotational motion of the wingstructures (221) about the axis of the pertinent coupling shaft (171).Similar shaft and bearing configurations are utilized to provide forrotation of the control element pulleys (167) relative to the wingstructures (221). Thus, the winged split carriage design is configuredto allow for independent motion of each of two wing structures (221),while also allowing for independent rotational motion of two sets ofcontrol element pulleys (167) and thereby instrument interface sockets(161). In other words, with a winged guide instrument (215) such as thatdepicted in FIG. 103.1 coupled to an instrument base mounting plate(187) having an arcuate slot (145), and two control element interfaceassemblies (147) coupled to two instrument interface sockets positionedbelow the mounting plate (187) in the configuration depicted in FIG.103.1, each of the control element interface assemblies (147) may berotated about their longitudinal axis (169), and also arcuatelytranslated through the arcuate slot (145) formed in the instrument base(141), to provide for tensioning and control of two control elements,one around each of the control element pulleys (167) on each of thecontrol element interface assemblies (147), with actuation of a singlecontrol element interface assembly (147). Thus four control elements maybe driven with the actuation of only two control element interfaceassemblies (147).

Referring to FIG. 103.10, an exploded view of an assembly similar tothat depicted in FIG. 103.1 is depicted. The sheath instrument (30), thetwo control element interface assemblies (147), and the guide catheterinstrument member of FIG. 103.1 are illustrated in FIG. 103.10. As withaforementioned embodiments, the instrument driver roll assembly (195)and instrument driver motor/gear assembly (193) are coupled to the frameof the main housing structure (137) of the instrument driver. As shownin FIG. 103.11, redundant encoder readers (211) associated with each offour control element drive motors (209) of this embodiment facilitatehigh precision rotational position readings of the motor shafts andprevent position read errors. The motor output shafts are coupled tobevel gears (207) which are interfaced with another set of bevel gears(213) and thereby configured to drive the depicted vertical outputshafts (205). The motor/gear interface block (203) is utilized to couplethe motors, gears, and shafts into positions relative to each other andthe main frame of the instrument driver (not shown), while constrainingmotions generally to rotational motions of shafts, motors, gears, andbearings. The rotation and arcuate translation of the winged structureinstrument interface sockets (161) relative to the winged carriage base(173) and wing structures (221) is a key difference between the wingedsplit carriage instrument driver and the non-winged embodimentsdescribed herein.

Referring to FIG. 104, one embodiment of an operator control station isdepicted showing a control button console (8), a computer (6), acomputer control interface device (10), such as a mouse, a visualdisplay system (4) and a master input device (12). In addition tobuttons on the button console (8), footswitches and other known typesuser control interfaces may be utilized to provide an operator interfacewith the system controls. Referring to FIG. 105A, in one embodiment, themaster input device (12) is a multi-degree-of-freedom device havingmultiple joints and associated encoders (306). An operator interface(217) is configured for comfortable interfacing with the human fingers.The depicted embodiment of the operator interface (217) is substantiallyspherical. Further, the master input device may have integrated hapticscapability for providing tactile feedback to the user. Anotherembodiment of a master input device (12) is depicted in FIG. 105B havinga similarly-shaped operator interface (217). Suitable master inputdevices are available from manufacturers such as SensAble Technologies,Inc. of Woburn, Mass. under the trade name Phantom® Haptic Devices orfrom Force Dimension of Lausanne, Switzerland under the trade name OmegaHaptic Device. In one embodiment featuring an Omega-type master inputdevice, the motors of the master input device are utilized for gravitycompensation. In other words, when the operator releases the masterinput device from his hands, the master input device is configured tostay in position, or hover around the point at which is was left, oranother predetermined point, without gravity taking the handle of themaster input device to the portion of the master input device's range ofmotion closest to the center of the earth. In another embodiment, hapticfeedback is utilized to provide feedback to the operator that he hasreached the limits of the pertinent instrument workspace. In anotherembodiment, haptic feedback is utilized to provide feedback to theoperator that he has reached the limits of the subject tissue workspacewhen such workspace has been registered to the workspace of theinstrument (i.e., should the operator be navigating a tool such as anablation tip with a guide instrument through a 3-D model of a heartimported, for example, from CT data of an actual heart, the master inputdevice is configured to provide haptic feedback to the operator that hehas reached a wall or other structure of the heart as per the data ofthe 3-D model, and therefore help prevent the operator from driving thetool through such wall or structure without at least feeling the wall orstructure through the master input device). In another embodiment,contact sensing technologies configured to detect contact between aninstrument and tissue may be utilized in conjunction with the hapticcapability of the master input device to signal the operator that theinstrument is indeed in contact with tissue.

Referring to FIGS. 106A-109, the basic kinematics of a catheter withfour control elements is reviewed.

Referring to FIGS. 106A-B, as tension is placed only upon the bottomcontrol element (312), the catheter (90) bends downward, as shown inFIG. 106A. Similarly, pulling the left control element (314) in FIGS.107A-B bends the catheter (90) left, pulling the right control element(310) in FIGS. 108A-B bends the catheter (90) right, and pulling the topcontrol element (308) in FIGS. 109A-B bends the catheter (90) up. Aswill be apparent to those skilled in the art, well-known combinations ofapplied tension about the various control elements results in a varietyof bending configurations at the tip of the catheter member (90). One ofthe challenges in accurately controlling a catheter or similar elongatemember with tension control elements is the retention of tension incontrol elements, which may not be the subject of the majority of thetension loading applied in a particular desired bending configuration.If a system or instrument is controlled with various levels of tension,then losing tension, or having a control element in a slackconfiguration, can result in an unfavorable control scenario.

Referring to FIGS. 110A-E, a simple scenario is useful in demonstratingthis notion. As shown in FIG. 110A, a simple catheter (316) steered withtwo control elements (314, 310) is depicted in a neutral position. Ifthe left control element (314) is placed into tension greater than thetension, if any, which the right control element (310) experiences, thecatheter (316) bends to the left, as shown in FIG. 110B. If a change ofdirection is desired, this paradigm needs to reverse, and the tension inthe right control element (310) needs to overcome that in the leftcontrol element (314). At the point of a reversal of direction likethis, where the tension balance changes from left to right, withoutslack or tension control, the right most control element (310) maygather slack which needs to be taken up before precise control can bereestablished. Subsequent to a “reeling in” of slack which may bepresent, the catheter (316) may be may be pulled in the oppositedirection, as depicted in FIGS. 110C-E, without another slack issue froma controls perspective until a subsequent change in direction.

The above-described instrument embodiments present various techniquesfor managing tension control in various guide instrument systems havingbetween two and four control elements. For example, in one set ofembodiments, tension may be controlled with active independenttensioning of each control element in the pertinent guide catheter viaindependent control element interface assemblies (132) associated withindependently-controlled guide instrument interface sockets (270) on theinstrument driver (16). Thus, tension may be managed by independentlyactuating each of the control element interface assemblies (132) in afour-control-element embodiment, such as that depicted in FIGS. 17 and47, a three-control-element embodiment, such as that depicted in FIGS.63 and 64, or a two-control-element embodiment, such as that depicted inFIGS. 56 and 66.

In another set of embodiments, tension may be controlled with activeindependent tensioning with a split carriage design, as described inreference to FIG. 102. For example, with an instrument embodimentsimilar to that depicted in FIGS. 53, 54, and 56, a split carriage withtwo independent linearly movable portions, such as that depicted in FIG.102, may be utilized to actively and independently tension each of thetwo control element interface assemblies, each of which is associatedwith two dimensions of a given degree of freedom. For example, there canbe + and − pitch on one interface assembly, + and − yaw on the otherinterface assembly, with slack or tension control provided for pitch byone of the linearly movable portions (302) of the split carriage (296),and slack or tension control provided for yaw by the other linearlymovable portion (302) of the split carriage (296).

Similarly, with an embodiment similar to that of FIGS. 71-73, slack ortension control for a single degree of freedom, such as yaw or pitch,may be provided by a single-sided split carriage design similar to thatof FIG. 102, with the exception that only one linearly movable portionwould be required to actively tension the single control elementinterface assembly of an instrument.

In another set of embodiments, tensioning may be controlled withspring-loaded idlers configured to keep the associated control elementsout of slack, as in the embodiments depicted in FIGS. 57-62 and 69-70.The control elements preferably are pre-tensioned in each embodiment toprevent slack and provide predictable performance. Indeed, in yetanother set of embodiments, pre-tensioning may form the main source oftension management, as in the embodiments depicted in FIGS. 55 and67-68. In the case of embodiments only having pre-tensioning orspring-loaded idler tensioning, the control system may need to beconfigured to reel in bits of slack at certain transition points incatheter bending, such as described above in relation to FIGS. 110A-B.

To accurately coordinate and control actuations of various motors withinan instrument driver from a remote operator control station such as thatdepicted in FIG. 1, an advanced computerized control and visualizationsystem is preferred. While the control system embodiments that followare described in reference to a particular control systems interface,namely the Simulink® and xPC Target control interfaces available fromThe MathWorks, Inc. of Natick, Mass., and PC-based computerized hardwareconfigurations, many other configurations may be utilized, includingvarious pieces of specialized hardware, in place of more flexiblesoftware controls running on PC-based systems.

Referring to FIG. 111, an overview of an embodiment of a controls systemflow is depicted. A master computer (400) running master input devicesoftware, visualization software, instrument localization software, andsoftware to interface with operator control station buttons and/orswitches is depicted. In one embodiment, the master input devicesoftware is a proprietary module packaged with an off-the-shelf masterinput device system, such as the Phantom® from SensAble Technologies,Inc., which is configured to communicate with the Phantom® Haptic Devicehardware at a relatively high frequency as prescribed by themanufacturer. Other suitable master input devices, such as that (12)depicted in FIG. 105B are available from suppliers such as ForceDimension of Lausanne, Switzerland. The master input device (12) mayalso have haptics capability to facilitate feedback to the operator, andthe software modules pertinent to such functionality may also beoperated on the master computer (400). Preferred embodiments of hapticsfeedback to the operator are discussed in further detail below.

The term “localization” is used in the art in reference to systems fordetermining and/or monitoring the position of objects, such as medicalinstruments, in a reference coordinate system. In one embodiment, theinstrument localization software is a proprietary module packaged withan off-the-shelf or custom instrument position tracking system, such asthose available from Ascension Technology Corporation of Burlington,Vt.; Biosense Webster, Inc. of Diamond Bar, Calif.; EndocardialSolutions—St. Jude Medical, Inc. of St. Paul, Minn.; EPTechnologies—Boston Scientific Corporation of Natick, Mass.; Medtronic,Inc. of Minneapolis, Minn.; and others. Such systems may be capable ofproviding not only real-time or near real-time positional information,such as X-Y-Z coordinates in a Cartesian coordinate system, but alsoorientation information relative to a given coordinate axis or system.Some of the commercially-available localization systems useelectromagnetic relationships to determine position and/or orientation,while others, such as some of those available from EndocardialSolutions—St Jude Medical, Inc., utilize potential difference orvoltage, as measured between a conductive sensor located on thepertinent instrument and conductive portions of sets of patches placedagainst the skin, to determine position and/or orientation. Referring toFIGS. 112A and 112B, various localization sensing systems may beutilized with the various embodiments of the robotic catheter systemdisclosed herein. In other embodiments not comprising a localizationsystem to determine the position of various components, kinematic and/orgeometric relationships between various components of the system may beutilized to predict the position of one component relative to theposition of another. Some embodiments may utilize both localization dataand kinematic and/or geometric relationships to determine the positionsof various components.

As shown in FIG. 112A, one preferred localization system comprises anelectromagnetic field transmitter (406) and an electromagnetic fieldreceiver (402) positioned within the central lumen of a guide catheter(90). The transmitter (406) and receiver (402) are interfaced with acomputer operating software configured to detect the position of thedetector relative to the coordinate system of the transmitter (406) inreal or near-real time with high degrees of accuracy. Referring to FIG.112B, a similar embodiment is depicted with a receiver (404) embeddedwithin the guide catheter (90) construction. Preferred receiverstructures may comprise three or more sets of very small coils spatiallyconfigured to sense orthogonal aspects of magnetic fields emitted by atransmitter. Such coils may be embedded in a custom configuration withinor around the walls of a preferred catheter construct. For example, inone embodiment, two orthogonal coils are embedded within a thinpolymeric layer at two slightly flattened surfaces of a catheter (90)body approximately ninety degrees orthogonal to each other about thelongitudinal axis of the catheter (90) body, and a third coil isembedded in a slight polymer-encapsulated protrusion from the outside ofthe catheter (90) body, perpendicular to the other two coils. Due to thevery small size of the pertinent coils, the protrusion of the third coilmay be minimized. Electronic leads for such coils may also be embeddedin the catheter wall, down the length of the catheter body to aposition, preferably adjacent an instrument driver, where they may berouted away from the instrument to a computer running localizationsoftware and interfaced with a pertinent transmitter.

In another similar embodiment (not shown), one or more conductive ringsmay be electronically connected to a potential-difference-basedlocalization/orientation system, along with multiple sets, preferablythree sets, of conductive skin patches, to provide localization and/ororientation data utilizing a system such as those available fromEndocardial Solutions—St. Jude Medical, Inc. The one or more conductiverings may be integrated into the walls of the instrument at variouslongitudinal locations along the instrument, or set of instruments. Forexample, a guide instrument may have several conductive ringslongitudinally displaced from each other toward the distal end of theguide instrument, while a coaxially-coupled sheath instrument maysimilarly have one or more conductive rings longitudinally displacedfrom each other toward the distal end of the sheath instrument—toprovide precise data regarding the location and/or orientation of thedistal ends of each of such instruments.

Referring back to FIG. 111, in one embodiment, visualization softwareruns on the master computer (400) to facilitate real-time driving andnavigation of one or more steerable instruments. In one embodiment,visualization software provides an operator at an operator controlstation (2), such as that depicted in FIG. 1, with a digitized dashboardor windshield display to enhance instinctive drivability of thepertinent instrumentation within the pertinent tissue structures.Referring to FIG. 113, a simple illustration is useful to explain oneembodiment of a preferred relationship between visualization andnavigation with a master input device (12). In the depicted embodiment,two display views (410, 412) are shown. One preferably represents aprimary navigation view (410) and one may represent a secondarynavigation view (412). To facilitate instinctive operation of thesystem, it is preferable to have the master input device coordinatesystem at least approximately synchronized with the coordinate system ofat least one of the two views. Further, it is preferable to provide theoperator with one or more secondary views which may be helpful innavigating through challenging tissue structure pathways and geometries.

Using the operation of an automobile as an example, if the master inputdevice is a steering wheel and the operator desires to drive a car in aforward direction using one or more views, his first priority is likelyto have a view straight out the windshield, as opposed to a view out theback window, out one of the side windows, or from a car in front of thecar that he is operating. The operator might prefer to have the forwardwindshield view as his primary display view, such that a right turn onthe steering wheel takes him right as he observes his primary display, aleft turn on the steering wheel takes him left, and so forth. If theoperator of the automobile is trying to park the car adjacent anothercar parked directly in front of him, it might be preferable to also havea view from a camera positioned, for example, upon the sidewalk aimedperpendicularly through the space between the two cars (one driven bythe operator and one parked in front of the driven car), so the operatorcan see the gap closing between his car and the car in front of him ashe parks. While the driver might not prefer to have to completelyoperate his vehicle with the sidewalk perpendicular camera view as hissole visualization for navigation purposes, this view is helpful as asecondary view.

Referring still to FIG. 113, if an operator is attempting to navigate asteerable catheter in order to, for example, contact a particular tissuelocation with the catheter's distal tip, a useful primary navigationview (410) may comprise a three dimensional digital model of thepertinent tissue structures (414) through which the operator isnavigating the catheter with the master input device (12), along with arepresentation of the catheter distal tip location (416) as viewed alongthe longitudinal axis of the catheter near the distal tip. Thisembodiment illustrates a representation of a targeted tissue structurelocation (418), which may be desired in addition to the tissue digitalmodel (414) information. A useful secondary view (412) displayed upon adifferent monitor or in a different window upon the same monitor or evenwithin the same user interface window, for example, may comprise anorthogonal view representation depicting the catheter tip location (416)and also perhaps a catheter body representation (420) to facilitate theoperator's driving of the catheter tip toward the desired targetedtissue location (418).

In one embodiment, subsequent to development and display of a digitalmodel of pertinent tissue structures, an operator may select one primaryand at least one secondary view to facilitate navigation of theinstrumentation. By selecting which view is a primary view, the user canautomatically toggle a master input device (12) coordinate system tosynchronize with the selected primary view. In an embodiment with theleftmost depicted view (410) selected as the primary view, to navigatetoward the targeted tissue site (418), the operator should manipulatethe master input device (12) forward, to the right, and down. The rightview will provide valued navigation information, but will not be asinstinctive from a “driving” perspective.

To illustrate: if the operator wishes to insert the catheter tip towardthe targeted tissue site (418) watching only the rightmost view (412)without the master input device (12) coordinate system synchronized withsuch view, the operator would have to remember that pushing straightahead on the master input device will make the distal tip representation(416) move to the right on the rightmost display (412). Should theoperator decide to toggle the system to use the rightmost view (412) asthe primary navigation view, the coordinate system of the master inputdevice (12) is then synchronized with that of the rightmost view (412),enabling the operator to move the catheter tip (416) closer to thedesired targeted tissue location (418) by manipulating the master inputdevice (12) down and to the right.

The synchronization of coordinate systems described herein may beconducted using fairly conventional mathematic relationships. Forexample, in one embodiment, the orientation of the distal tip of thecatheter may be measured using a 6-axis position sensor system such asthose available from Ascension Technology Corporation, Biosense Webster,Inc., Endocardial Solutions—St. Jude Medical, Inc., EPTechnologies—Boston Scientific Corporation, and others. A 3-axiscoordinate frame C for locating the distal tip of the catheter isconstructed from this orientation information. The orientationinformation is used to construct the homogeneous transformation matrix,T_(C0) ^(G0), which transforms a vector in the Catheter coordinate frameC to the fixed Global coordinate frame G in which the sensormeasurements are done (the subscript C₀ and superscript G₀ are used torepresent the 0'th, or initial, step). As a registration step, thecomputer graphics view of the catheter is rotated until the master inputand the computer graphics view of the catheter distal tip motion arecoordinated and aligned with the camera view of the graphics scene. The3-axis coordinate frame transformation matrix T_(Gref) ^(G0) for thecamera position of this initial view is stored (subscripts G_(ref) andsuperscript C_(ref) stand for the global and camera “reference” views).The corresponding catheter “reference view” matrix for the cathetercoordinates is obtained as:T _(Cref) ^(C0) =T _(G0) ^(C0) T _(Gref) ^(G0) T _(Cref) ^(Gref)=(T_(C0) ^(G0))⁻¹ T _(Gref) ^(G0) T _(C1) ^(G1)

Also note that the catheter's coordinate frame is fixed in the globalreference frame G, thus the transformation matrix between the globalframe and the catheter frame is the same in all views, i.e., T_(C0)^(G0)=T_(Cref) ^(Gref)=T_(C1) ^(G1) for any arbitrary view i.

The coordination between primary view and master input device coordinatesystems is achieved by transforming the master input as follows: Givenany arbitrary computer graphics view of the representation, e.g. thei'th view, the 3-axis coordinate frame transformation matrix T_(Gi)^(G0) of the camera view of the computer graphics scene is obtained formthe computer graphics software. The corresponding cathetertransformation matrix is computed in a similar manner as above:T _(Ci) ^(C0) =T _(G0) ^(C0) T _(Gi) ^(G0) T _(Ci) ^(Gi)=(T _(C0)^(G0))⁻¹ T _(Gi) ^(G0) T _(Ci) ^(Gi)

The transformation that needs to be applied to the master input whichachieves the view coordination is the one that transforms from thereference view that was registered above, to the current ith view, i.e.,T_(Cref) ^(Ci). Using the previously computed quantities above, thistransform is computed as:T _(Cref) ^(Ci) =T _(C0) ^(Ci) T _(Cref) ^(C0)

The master input is transformed into the commanded catheter input byapplication of the transformation T_(Cref) ^(Ci). Given a command input

${r_{master} = \begin{bmatrix}x_{master} \\y_{master} \\y_{master}\end{bmatrix}},$one may calculate:

$r_{catheter} = {\begin{bmatrix}x_{catheter} \\y_{catheter} \\y_{catheter}\end{bmatrix} = {{T_{Cref}^{Ci}\begin{bmatrix}x_{master} \\y_{master} \\y_{master}\end{bmatrix}}.}}$

Under such relationships, coordinate systems of the primary view andmaster input device may be aligned for instinctive operation.

Referring back to embodiment of FIG. 111, the master computer (400) alsocomprises software and hardware interfaces to operator control stationbuttons, switches, and other input devices which may be utilized, forexample, to “freeze” the system by functionally disengaging the masterinput device as a controls input, or provide toggling between variousscaling ratios desired by the operator for manipulated inputs at themaster input device (12). The master computer (400) has two separatefunctional connections with the control and instrument driver computer(422): a first connection (426) for passing controls and visualizationrelated commands, such as commands for a desired XYZ in the cathetercoordinate system and a second connection (428) for passing safetysignal commands. Similarly, the control and instrument driver computer(422) has two separate functional connections with the instrument andinstrument driver hardware (424): a first connection (430) for passingcontrol and visualization related commands such asrequired-torque-related voltages to the amplifiers to drive the motorsand encoders and a second connection (432) for passing safety signalcommands.

In one embodiment, the safety signal commands represent a simple signalrepeated at very short intervals, such as every 10 milliseconds, suchsignal chain being logically read as “system is ok, amplifiers stayactive”. If there is any interruption in the safety signal chain, theamplifiers are logically toggled to inactive status and the instrumentcannot be moved by the control system until the safety signal chain isrestored. Also shown in the signal flow overview of FIG. 111 is apathway (434) between the physical instrument and instrument driverhardware back to the master computer to depict a closed loop systemembodiment wherein instrument localization technology, such as thatdescribed in reference to FIGS. 112A-B, is utilized to determine theactual position of the instrument to minimize navigation and controlerror, as described in further detail below.

FIGS. 114-124 depict various aspects of one embodiment of a SimuLink®software control schema for an embodiment of the physical system, withparticular attention to an embodiment of a “master following mode.” Inthis embodiment, an instrument is driven by following instructions froma master input device, and a motor servo loop embodiment, whichcomprises key operational functionality for executing upon commandsdelivered from the master following mode to actuate the instrument.

FIG. 114 depicts a high-level view of an embodiment wherein any one ofthree modes may be toggled to operate the primary servo loop (436). Inidle mode (438), the default mode when the system is started up, all ofthe motors are commanded via the motor servo block (444) to servo abouttheir current positions, their positions being monitored with digitalencoders associated with the motors. In other words, idle mode (438)deactivates the motors, while the remaining system stays active. Thus,when the operator leaves idle mode, the system knows the position of therelative components. In auto home mode (440), cable loops within anassociated instrument driver, such as that depicted in FIG. 98, arecentered within their cable loop range to ensure substantiallyequivalent range of motion of an associated instrument, such as thatdepicted in FIG. 17, in both directions for a various degree of freedom,such as + and − directions of pitch or yaw, when loaded upon theinstrument driver. This is a setup mode for preparing an instrumentdriver before an instrument is engaged.

In master following mode (442), the control system receives signals fromthe master input device, and in a closed loop embodiment from both amaster input device and a localization system, and forwards drivesignals to the primary servo loop (436) to actuate the instrument inaccordance with the forwarded commands. Aspects of this embodiment ofthe master following mode (442) are depicted in further detail in FIGS.119-124. Aspects of the primary servo loop and motor servo block (444)are depicted in further detail in FIGS. 115-118.

Referring to FIG. 119, a more detailed functional diagram of anembodiment of master following mode (442) is depicted. As shown in FIG.119, the inputs to functional block (446) are XYZ position of the masterinput device in the coordinate system of the master input device which,per a setting in the software of the master input device may be alignedto have the same coordinate system as the catheter, and localization XYZposition of the distal tip of the instrument as measured by thelocalization system in the same coordinate system as the master inputdevice and catheter. Referring to FIG. 120 for a more detailed view offunctional block (446) of FIG. 119, a switch (460) is provided at blockto allow switching between master inputs for desired catheter position,to an input interface (462) through which an operator may command thatthe instrument go to a particular XYZ location in space. Variouscontrols features may also utilize this interface to provide an operatorwith, for example, a menu of destinations to which the system shouldautomatically drive an instrument, etc. Also depicted in FIG. 120 is amaster scaling functional block (451) which is utilized to scale theinputs coming from the master input device with a ratio selectable bythe operator. The command switch (460) functionality includes a low passfilter to weight commands switching between the master input device andthe input interface (462), to ensure a smooth transition between thesemodes.

Referring back to FIG. 119, desired position data in XYZ terms is passedto the inverse kinematics block (450) for conversion to pitch, yaw, andextension (or “insertion”) terms in accordance with the predictedmechanics of materials relationships inherent in the mechanical designof the instrument.

The kinematic relationships for many catheter instrument embodiments maybe modeled by applying conventional mechanics relationships. In summary,a control-element-steered catheter instrument is controlled through aset of actuated inputs. In a four-control-element catheter instrument,for example, there are two degrees of motion actuation, pitch and yaw,which both have + and − directions. Other motorized tensionrelationships may drive other instruments, active tensioning, orinsertion or roll of the catheter instrument. The relationship betweenactuated inputs and the catheter's end point position as a function ofthe actuated inputs is referred to as the “kinematics” of the catheter.

Referring to FIG. 125, the “forward kinematics” expresses the catheter'send-point position as a function of the actuated inputs while the“inverse kinematics” expresses the actuated inputs as a function of thedesired end-point position. Accurate mathematical models of the forwardand inverse kinematics are essential for the control of a roboticallycontrolled catheter system. For clarity, the kinematics equations arefurther refined to separate out common elements, as shown in FIG. 125.The basic kinematics describes the relationship between the taskcoordinates and the joint coordinates. In such case, the taskcoordinates refer to the position of the catheter end-point while thejoint coordinates refer to the bending (pitch and yaw, for example) andlength of the active catheter. The actuator kinematics describes therelationship between the actuation coordinates and the jointcoordinates. The task, joint, and bending actuation coordinates for therobotic catheter are illustrated in FIG. 126. By describing thekinematics in this way we can separate out the kinematics associatedwith the catheter structure, namely the basic kinematics, from thoseassociated with the actuation methodology.

The development of the catheter's kinematics model is derived using afew essential assumptions. Included are assumptions that the catheterstructure is approximated as a simple beam in bending from a mechanicsperspective, and that control elements, such as thin tension wires,remain at a fixed distance from the neutral axis and thus impart auniform moment along the length of the catheter.

In addition to the above assumptions, the geometry and variables shownin FIG. 127 are used in the derivation of the forward and inversekinematics. The basic forward kinematics, relating the catheter taskcoordinates (X_(c), Y_(c), Z_(c)) to the joint coordinates (_(pitch),_(pitch), L), is given as follows:

X_(c) = ws(θ)$Y_{c} = {{R\mspace{14mu}{\sin(\alpha)}Z_{c}} = {{w\mspace{14mu}{\sin(\theta)}{where}w} = {{R\left( {1 - {\cos(\alpha)}} \right)}\begin{matrix}{\alpha = \left\lbrack {\left( \phi_{pitch} \right)^{2} + \left( \phi_{yaw} \right)^{2}} \right\rbrack^{1/2}} & \left( {{total}\mspace{14mu}{bending}} \right) \\{R = \frac{L}{\alpha}} & \left( {{bend}\mspace{14mu}{radius}} \right) \\{\theta = {{atan}\; 2\left( {\phi_{pitch},\phi_{yaw}} \right)}} & \left( {{roll}\mspace{14mu}{angle}} \right)\end{matrix}}}}$

The actuator forward kinematics, relating the joint coordinates_(pitch), _(pitch), L) to the actuator coordinates (L_(x), L_(z), L) isgiven as follows:

$\phi_{pitch} = \frac{2\Delta\; L_{z}}{D_{c}}$$\phi_{yaw} = \frac{2\Delta\; L_{x}}{D_{c}}$

As illustrated in FIG. 125, the catheter's end-point position can bepredicted given the joint or actuation coordinates by using the forwardkinematics equations described above.

Calculation of the catheter's actuated inputs as a function of end-pointposition, referred to as the inverse kinematics, can be performednumerically, using a nonlinear equation solver such as Newton-Raphson. Amore desirable approach, and the one used in this illustrativeembodiment, is to develop a closed-form solution which can be used tocalculate the required actuated inputs directly from the desiredend-point positions.

As with the forward kinematics, we separate the inverse kinematics intothe basic inverse kinematics, which relates joint coordinates to thetask coordinates, and the actuation inverse kinematics, which relatesthe actuation coordinates to the joint coordinates. The basic inversekinematics, relating the joint coordinates (_(pitch), _(pitch), L), tothe catheter task coordinates (Xc, Yc, Zc) is given as follows:

ϕ_(pitch) = α sin (θ) ϕ_(yaw) = α cos (θ) L = R α $\begin{matrix}\; & {\theta = {{atan}\; 2\left( {Z_{c},X_{c}} \right)}} & {\beta = {{atan}\; 2\left( {Y_{c}W_{c}} \right)}} \\\left. \rightarrow\mspace{14mu}\left. {where}\rightarrow\mspace{14mu}\rightarrow \right. \right. & {R = \frac{l\mspace{14mu}\sin\mspace{14mu}\beta}{\sin\mspace{14mu} 2\beta}} & {\left. \rightarrow\mspace{14mu} W_{c} \right. = \left( {X_{c}^{2} + Z_{c}^{2}} \right)^{\frac{1}{2}}} \\\; & {\alpha = {\pi - {2\beta}}} & {l = \left( {W_{c}^{2} + Y_{c}^{2}} \right)^{\frac{1}{2}}}\end{matrix}$

The actuator inverse kinematics, relating the actuator coordinates(L_(x), L_(z), L) to the joint coordinates (_(pitch), _(pitch), L) isgiven as follows:

${\Delta\; L_{x}} = \frac{D_{c}\phi_{yaw}}{2}$${\Delta\; L_{z}} = \frac{D_{c}\phi_{pitch}}{2}$

Referring back to FIG. 119, pitch, yaw, and extension commands arepassed from the inverse kinematics block (450) to a position controlblock (448) along with measured localization data. FIG. 124 provides amore detailed view of the position control block (448). After measuredXYZ position data comes in from the localization system, it goes througha inverse kinematics block (464) to calculate the pitch, yaw, andextension the instrument needs to have in order to travel to where itneeds to be. Comparing (466) these values with filtered desired pitch,yaw, and extension data from the master input device, integralcompensation is then conducted with limits on pitch and yaw to integrateaway the error. In this embodiment, the extension variable does not havethe same limits (468), as do pitch and yaw (470). As will be apparent tothose skilled in the art, having an integrator in a negative feedbackloop forces the error to zero. Desired pitch, yaw, and extensioncommands are next passed through a catheter workspace limitation block(452), which may be a function of the experimentally determined physicallimits of the instrument beyond which componentry may fail, deformundesirably, or perform unpredictably or undesirably. This workspacelimitation essentially defines a volume similar to a cardioid-shapedvolume about the distal end of the instrument. Desired pitch, yaw, andextension commands, limited by the workspace limitation block, are thenpassed to a catheter roll correction block (454).

This functional block is depicted in further detail in FIG. 121, andessentially comprises a rotation matrix for transforming the pitch, yaw,and extension commands about the longitudinal, or “roll”, axis of theinstrument—to calibrate the control system for rotational deflection atthe distal tip of the catheter that may change the control elementsteering dynamics. For example, if a catheter has no rotationaldeflection, pulling on a control element located directly up at twelveo'clock should urge the distal tip of the instrument upward. If,however, the distal tip of the catheter has been rotationally deflectedby, say, ninety degrees clockwise, to get an upward response from thecatheter, it may be necessary to tension the control element that wasoriginally positioned at a nine o'clock position. The catheter rollcorrection schema depicted in FIG. 121 provides a means for using arotation matrix to make such a transformation, subject to a rollcorrection angle, such as the ninety degrees in the above example, whichis input, passed through a low pass filter, turned to radians, and putthrough rotation matrix calculations.

In one embodiment, the roll correction angle is determined throughexperimental experience with a particular instrument and path ofnavigation. In another embodiment, the roll correction angle may bedetermined experimentally in-situ using the accurate orientation dataavailable from the preferred localization systems. In other words, withsuch an embodiment, a command to, for example, bend straight up can beexecuted, and a localization system can be utilized to determine atwhich angle the defection actually went—to simply determine the in-situroll correction angle.

Referring briefly back to FIG. 119, roll corrected pitch and yawcommands, as well as unaffected extension commands, are output from thecatheter roll correction block (454) and may optionally be passed to aconventional velocity limitation block (456). Referring to FIG. 122,pitch and yaw commands are converted from radians to degrees, andautomatically controlled roll may enter the controls picture to completethe current desired position (472) from the last servo cycle. Velocityis calculated by comparing the desired position from the previous servocycle, as calculated with a conventional memory block calculation (476),with that of the incoming commanded cycle. A conventional saturationblock (474) keeps the calculated velocity within specified values, andthe velocity-limited command (478) is converted back to radians andpassed to a tension control block (458).

Tension within control elements may be managed depending upon theparticular instrument embodiment, as described above in reference to thevarious instrument embodiments and tension control mechanisms. As anexample, FIG. 123 depicts a pre-tensioning block (480) with which agiven control element tension is ramped to a present value. Anadjustment is then added to the original pre-tensioning based upon apreferably experimentally-tuned matrix pertinent to variables, such asthe failure limits of the instrument construct and the incomingvelocity-limited pitch, yaw, extension, and roll commands. This adjustedvalue is then added (482) to the original signal for output, via gearratio adjustment, to calculate desired motor rotation commands for thevarious motors involved with the instrument movement. In thisembodiment, extension, roll, and sheath instrument actuation (484) haveno pre-tensioning algorithms associated with their control. The outputis then complete from the master following mode functionality, and thisoutput is passed to the primary servo loop (436).

Referring back to FIG. 114, incoming desired motor rotation commandsfrom either the master following mode (442), auto home mode (440), oridle mode (438) in the depicted embodiment are fed into a motor servoblock (444), which is depicted in greater detail in FIGS. 115-118.

Referring to FIG. 115, incoming measured motor rotation data fromdigital encoders and incoming desired motor rotation commands arefiltered using conventional quantization noise filtration at frequenciesselected for each of the incoming data streams to reduce noise while notadding undue delays which may affect the stability of the controlsystem. As shown in FIGS. 117 and 118, conventional quantizationfiltration is utilized on the measured motor rotation signals at about200 hertz in this embodiment, and on the desired motor rotation commandat about 15 hertz. The difference (488) between the quantizationfiltered values forms the position error which may be passed through alead filter, the functional equivalent of a proportional derivative(“PD”)+low pass filter. In another embodiment, conventional PID,lead/lag, or state space representation filter may be utilized. The leadfilter of the depicted embodiment is shown in further detail in FIG.116.

In particular, the lead filter embodiment in FIG. 116 comprises avariety of constants selected to tune the system to achieve desiredperformance. The depicted filter addresses the needs of one embodimentof a 4-control element guide catheter instrument with independentcontrol of each of four control element interface assemblies for +/−pitch and +/− yaw, and separate roll and extension control. Asdemonstrated in the depicted embodiment, insertion and roll havedifferent inertia and dynamics as opposed to pitch and yaw controls, andthe constants selected to tune them is different. The filter constantsmay be theoretically calculated using conventional techniques and tunedby experimental techniques, or wholly determined by experimentaltechniques, such as setting the constants to give a sixty degree or morephase margin for stability and speed of response, a conventional phasemargin value for medical control systems.

In an embodiment where a tuned master following mode is paired with atuned primary servo loop, an instrument and instrument driver, such asthose described above, may be “driven” accurately in three-dimensionswith a remotely located master input device. Other preferred embodimentsincorporate related functionalities, such as haptic feedback to theoperator, active tensioning with a split carriage instrument driver,navigation utilizing direct visualization and/or tissue models acquiredin-situ and tissue contact sensing, and enhanced navigation logic.

Referring to FIG. 128, in one embodiment, the master input device may bea haptic master input device, such as those available from SensAbleTechnologies, Inc., under the trade name Phantom® Haptic Devices, andthe hardware and software required for operating such a device may atleast partially reside on the master computer. The master XYZ positionsmeasured from the master joint rotations and forward kinematics aregenerally passed to the master computer via a parallel port or similarlink and may subsequently be passed to a control and instrument drivercomputer. With such an embodiment, an internal servo loop for a Phantom®Haptic Device generally runs at a much higher frequency in the range of1,000 Hz, or greater, to accurately create forces and torques at thejoints of the master.

Referring to FIG. 129, a sample flowchart of a series of operationsleading from a position vector applied at the master input device to ahaptic signal applied back at the operator is depicted. A vector (344)associated with a master input device move by an operator may betransformed into an instrument coordinate system, and in particular to acatheter instrument tip coordinate system, using a simple matrixtransformation (345). The transformed vector (346) may then be scaled(347) per the preferences of the operator, to produce ascaled-transformed vector (348). The scaled-transformed vector (348) maybe sent to both the control and instrument driver computer (422)preferably via a serial wired connection, and to the master computer fora catheter workspace check (349) and any associated vector modification(350). This is followed by a feedback constant multiplication (351)chosen to produce preferred levels of feedback, such as force, in orderto produce a desired force vector (352), and an inverse transform (353)back to a force vector (354) in the master input device coordinatesystem for associated haptic signaling to the operator in thatcoordinate system.

A conventional Jacobian may be utilized to convert a desired forcevector (352) to torques desirably applied at the various motorscomprising the master input device, to give the operator a desiredsignal pattern at the master input device. Given this embodiment of asuitable signal and execution pathway, feedback to the operator in theform of haptics, or touch sensations, may be utilized in various ways toprovide added safety and instinctiveness to the navigation features ofthe system, as discussed in further detail below.

FIG. 130 is a system block diagram including haptics capability. Asshown in summary form in FIG. 130, encoder positions on the master inputdevice, changing in response to motion at the master input device, aremeasured (355), sent through forward kinematics calculations (356)pertinent to the master input device to get XYZ spatial positions of thedevice in the master input device coordinate system (357), thentransformed (358) to switch into the catheter coordinate system and(perhaps) transform for visualization orientation and preferred controlsorientation, to facilitate “instinctive driving”.

The transformed desired instrument position (359) may then be sent downone or more controls pathways to, for example, provide haptic feedback(360) regarding workspace boundaries or navigation issues, and provide acatheter instrument position control loop (361) with requisite catheterdesired position values, as transformed utilizing catheter inverse (362)kinematics relationships for the particular instrument into yaw, pitch,and extension, or insertion, terms (363) pertinent to operating theparticular catheter instrument with open or closed loop control.

Referring to FIGS. 131-136, relationships pertinent to tension controlvia a split carriage design such as that depicted in FIGS. 102A-B aredepicted to illustrate that such a design may isolate tension controlfrom actuation for each associated degree of freedom, such as pitch oryaw of a steerable catheter instrument.

Referring to FIG. 131, some of the structures associated with a splitcarriage design, such as the embodiments depicted in FIGS. 102 and 103,include a linearly movable portion (302), a guide instrument interfacesocket (270), a gear (300), and a rack (298). Applying conventionalgeometric relationships to the physical state of the structures relatedin FIG. 131, the equations (364, 365) of FIG. 132 may be generated.Utilizing forward kinematics of the instrument, such as those describedabove in reference to a pure cantilever bending model for a catheterinstrument, the relationships of FIG. 133 may be developed for theamount of bending as a function of cable pull and catheter diameter(“D_(c)”) as an actuation equation (366), and as a tension equation(367), wherein tension is defined as the total amount of common pull inthe control elements. Combining the equations of FIGS. 132 and 133, therelationships (368, 369) depicted in FIG. 134 can be obtained, whereindesired actuation (368) and desired tensioning (369) are decoupled bythe mechanics of the involved structures. Desired actuation (368) of theguide instrument interface socket (270) depicted in FIG. 131 is afunction of the socket's angular rotational position. Desired tensioning(369) of the associated control elements is a function of the positionof the tensioning gear (300) versus the rack (298).

Referring to FIG. 135, with a single degree of freedom actuated, such as+/− pitch or +/− yaw, and active tensioning via a split carriagemechanism, desired tension is linearly related to the absolute value ofthe amount of bending, as one would predict per the discussion above inreference to FIGS. 110A-E. The prescribed system never goes intoslack-desired tension is always positive, as shown in FIG. 135.Referring to FIG. 136, a similar relationship applies for a two degreeof freedom system with active tensioning—such as a four-cable systemwith +/− pitch and +/− yaw as the active degrees of freedom and activetensioning via a split carriage design. Because there are twodimensions, tension coupling terms (370) are incorporated to handleheuristic adjustments to, for example, minimize control element slackingand total instrument compression.

As discussed in reference to FIG. 113, in one embodiment, a tissuestructure model (414) may be utilized to enhance navigation. It isparticularly desirable to utilize actual data, acquired in situ, fromthe patient onto which a procedure is to be conducted, due to anatomicvariation among the patient population which may be significant,depending generally upon the subject tissue structures. For example, thegeometry of the left atrium of the human heart varies significantly frompatient to patient, according to published reports and experimentalverification in animals.

In one embodiment, focused magnetic resonance imaging, gated for heartcycle motion, and preferably gated for respiratory cycle motion, may beutilized along with conventional image cropping and thresholdingtechniques to produce a three dimensional tissue structure model. One ofthe challenges with such an imaging modality as applied to modelingactive tissue structures such as those of the heart is the gating. Inone embodiment, the gating comprises waiting for cardiac resting periodsduring diastole which are also correlated to substantially limitedrespiratory-induced motion. Acquiring a three-dimensional image of aleft atrium, for example, utilizing gated magnetic resonance, mayrequire an unacceptable amount of acquisition time, not to mention thegenerally large and expensive instrumentation required to accomplish theacquisition and fusion into a usable tissue structure model. Such amodality, however, may be preferred where cardiac and/or respiratorycyclic motion is negligible, and wherein an image or series of imagesmay be acquired and synthesized into a usable tissue structure modelcomparatively quickly.

Referring to FIGS. 137-139 a technique is depicted through which atissue structure model may be synthesized given appropriate hardware,such as an ultrasound transducer mounted upon a catheter or similarstructure, and a localization system mounted upon the same structure toenable the capture of not only ultrasound slice data, but also theposition and orientation of the transducer at the time of each sliceacquisition. In other embodiments, a similar robotic system does notinclude a localization system, in which case kinematic and/or geometricrelationships may be used to predict the location of the imaging device.

FIG. 137 depicts a human heart with a side-firing ultrasound catheter,such as those available under the trade name ACUSON AcuNav™ DiagnosticUltrasound Catheter by Siemens AG of Erlangen, Germany, entering theleft atrium via the inferior vena cava blood vessel. Coupled to theultrasound catheter, at or near the location of the ultrasoundtransducer, is a localization device, such as a set of orthogonallyoriented electromagnetic receiving coils, to determine the position andorientation of the ultrasound transducer at each acquired “slice” ofacquired reflected data. FIG. 138 is a view along the longitudinal axisof the distal end of the ultrasound catheter illustrating that, byrotating the ultrasound catheter, multiple slices (500) of reflectedultrasound image data, comprising multiple structural tissue masslocation points, may be acquired, along with the position andorientation of the ultrasound transducer for each slice of reflectedultrasound data. With such an embodiment and a targeted tissue structurethat is cyclically mobile, such the heart, each of the slices preferablyis acquired during the resting period of diastole to preventmotion-based image distortion.

In post-acquisition processing, the acquired image slice data andassociated position and orientation data may be utilized to construct athree-dimensional tissue structure model, such as that represented bythe series of slices in FIG. 139. As will be apparent to those skilledin the art, to achieve a finer mesh of points for image formation, moreslices may be acquired and assembled as shown in FIG. 139. Utilizingconventional image thresholding techniques available, for example, onmost ultrasound mainframe devices, such as that sold under the tradename ACUSON Sequoia™ ultrasound system by Siemens AG, points oftransition between blood or other fluid-filled cavity and tissue massmay be clearly resolved to establish transition points such as thosedepicted in FIG. 138.

Referring to FIGS. 140-148, various aspects of another embodiment foracquiring and compiling a tissue structure image is depicted. Referringto FIG. 140, applying similar principles as applied in reference to theembodiment of FIGS. 137-139, a perimetrically-firing ultrasound imageacquisition device, such as that sold under the trade name Ultra ICE™catheter by Boston Scientific Corporation, may be utilized in concertwith a localization system to acquire a series of perimetric slices(502) and associated position and orientation data for the transducer(504) to assemble a series of tissue-cavity threshold points (506)related in space, as depicted in FIG. 141. As illustrated in FIG. 140, aseries of related slices (502) is gathered as the transducer (504) isinserted, retrieved, or both, through a cavity. As with the embodimentabove, in the case of mobile heart tissue, each of the slices preferablyis acquired during the resting period of diastole to preventmotion-based image distortion. Further, a finer resolution tissuestructure image may be created with higher density image acquisition asthe transducer is repositioned within the targeted cavity, as will beapparent to those skilled in the art.

Referring to FIG. 142, a close-up isometric view of acircumferentially-firing ultrasound catheter device (508) comprising alocalization device (509) and an ultrasound transducer (510) is depictedwithin a tissue cavity acquiring a slice of data (511) with anillustrative measured point at a detected density threshold at thetransition between empty cavity and tissue wall. FIG. 143 depicts twoviews down the longitudinal axis of such a catheter system to depictacquisition of a series of density transition points about the catheterwhich form a slice which may be compiled into a larger three-dimensionalimage of the subject cavity. Referring to FIG. 144, the conventionaltransformation mathematics which may be utilized to transform positionand orientation data within the acquiring catheter tip frame ofreference to the ground frame of reference, or some other desired frameof reference. FIGS. 145A-B depict two different views of a catheter(512) inserting straight through a tissue cavity (513) and acquiring aseries of data slices (514) along the way.

FIGS. 146A-D depict respective variations for imaging a given tissuestructure geometry with the subject embodiment. In the embodimentdepicted in FIG. 146A, a circumferentially-firing ultrasound catheter(515) is inserted straight through a cavity without regard to incomingslice data. In FIG. 146B, a variation is depicted wherein the catheterstructure (515) carrying the ultrasound transducer and localizationdevice is bent as it moves through the subject tissue cavity to providea series of slices occupying substantially parallel planes. FIG. 146Cdepicts a variation wherein the catheter structure (515) carrying theultrasound transducer and localization device is directed into specificsub-portions of the subject tissue mass. In one embodiment, suchdirecting may be the result of real-time or near-real-time imageanalysis by the operator. For example, fluoroscopy or other conventionalimaging techniques may be utilized to position the catheter into such alocation in one embodiment. In another embodiment, the catheter may beautomatically or semi-automatically guided to such as position, asdiscussed below. As shown in FIG. 146D, the catheter (515) may beinserted and steered through the subject tissue cavity such that theplanes of the slices of data acquired are not parallel. Given the knownposition and orientation of the ultrasound transducer from an associatedlocalization system, it is by no means a requirement that the planeswithin a given image stack be parallel. Indeed, in some embodiments, itmay be desirable to controllably bend an imaging catheter (516) near alocation of interest to acquire multiple images (517) of a particularportion of the subject tissue, as depicted in FIG. 147. Such controlledbending through a preset range of motion as additional image slices areacquired may be termed “bend detailing” a particular portion of thesubject tissue structures.

Referring to FIGS. 148A-C, several acquisition protocol embodiments aredepicted for implementing the aforementioned acquisition systemembodiment. In a simple embodiment as illustrated in FIG. 148A, aninsertion vector is selected, subsequent to which an ultrasoundtransducer is inserted across a subject tissue cavity, pausing toacquire slice and position/orientation data along the way, leading tothe combination of slice and location/orientation data into athree-dimensional model. In another embodiment as shown in FIG. 148B,rather than following a pre-determined program for inserting across thesubject cavity and acquiring data slices, a closed-loop system analyzesincoming slice data and applies preprogrammed logic to automaticallynavigate as the image acquisition continues. FIG. 148C depicts anembodiment similar to that of FIG. 148B, with the exception that logicalpath planning is integrated into the controls logic operating thecatheter instrument driver to provide automated or semi-automated imageacquisition functionality. For example, the system may watch acquiredimages time-of-flight between emitted radiation and detected reflectionof such radiation to steer the instrument directly down the middle ofthe cavity, as interpreted utilizing the time-of-flight data. This maybe referred to as “time-of-flight center drive”. In another embodiment,significant changes in time-of-flight data for a given sector of animage series over a given period of time or distance may be interpretedas a change in tissue surface geometry worth higher density localizedimaging, or even an automatic bending to take the transducer closer tothe site of interest—or to rotate the transducer for higher-resolutionimaging of the particular area without insertion adjustment, asdescribed above in reference to FIG. 147.

FIGS. 149 and 150 depict respective embodiments for acquiring athree-dimensional tissue structure model of a human left atrium.

Referring to FIG. 149, subsequent to crossing the septal wall,confirming an acquisition start position adjacent the septum, andmeasuring the approximate trajectory and insertion length to reach theleft superior pulmonary vein funnel into the left atrium with theinstrument utilizing a conventional technology such as fluoroscopy orultrasound, the instrument may be driven across the left atrium cavityalong the approximate trajectory, gathering slices along the way andnoting, via time of flight calculations and anatomy logic, approximatepositioning of any other pulmonary vein funnel neckdown positions. Asthe instrument reaches the end of the predicted trajectory to the leftinferior pulmonary vein funnel, neckdown into the funnel may be detectedusing time of flight calculations and added data from bend-detailing, asdescribed above in reference to FIG. 147. After the neckdown isdetected, the instrument may be driven into the funnel and funnel shapeand trajectory data acquired for the left superior pulmonary veinstructure. In one embodiment, a preset insertion limit preventsinsertion beyond a set value into a pulmonary vein funnel structure. Inanother embodiment (such as that described in reference to FIG. 150), atissue contact sensing means may be utilized to provide feedback to anoperator or automated drive system that a tissue structure has beenphysically encountered by the instrument, and that the instrumentinsertion should be limited, as directed by the pertinent controlslogic.

Referring still to FIG. 149, subsequent to acquiring funnel shape andtrajectory data for a first pulmonary vein funnel of the left atrium, asimilar procedure may be utilized to do the same for second, third, andfourth pulmonary vein funnels. After driving back out of the leftsuperior pulmonary vein funnel, preferably along the trajectory utilizedto minimally invasively enter the funnel, the neckdown into the leftinferior pulmonary vein funnel is detected utilizing similar techniques,such as bend-detailing, and funnel and trajectory data pertinent to theleft inferior pulmonary vein is acquired. Subsequently, the instrumentmay be driven back to the location of the right pulmonary veinneckdowns, preferably starting with the more easily accessed, in mostpatients, right inferior pulmonary vein neckdown. To increase the amountand variation of data comprising the ultimate left atrium model, dataslices may be continually gathered as the instrument is driven back,forth, and around the left atrium.

After locating the right inferior pulmonary vein funnel, the instrumentmay be driven into the funnel and data acquired for the trajectory andshape, as discussed above in reference to the left pulmonary veinfunnels. Similar, shape and trajectory data may be acquired for theright superior pulmonary vein funnel, which in most patients, is themost difficult to access due to its location relative to the septum.Should bend-detailing or acquisition of slices and time of flightanalysis as facilitated by driving the instrument around within theatrium be ineffective in location any of the pulmonary vein neck downlocations, conventional systems, such as fluoroscopy or intracardiacultrasound, may be utilized during the depicted acquisition procedure toassist in generally driving the instrument to the location of thepertinent tissue structures, after which the appropriate portion of thedepicted procedure may be resumed in a more automated fashion.

Referring to FIG. 150, another embodiment of a procedure for acquiring athree-dimensional image of a left atrium is depicted, this embodimentdiffering from that of FIG. 149 in that the pertinent system alsoincorporates a contact sensing means at the distal tip of the instrumentfor sensing contact between the instrument tip and the subject tissuestructures. With such added functionality and logic to incorporate theinformation from it, the subject system may be configured to stop orindicate to the operator that a tissue structure or wall has beenengaged. Such a feature may be utilized to streamline the acquisitionprocess. For example, rather than planning a trajectory based upon datafrom imaging modalities such as fluoroscopy or ultrasound, theinstrument merely may be pointed in roughly the appropriate directionacross the left atrium toward the left pulmonary veins, and insertiondriving and data slice acquisition engaged. The contact sensing feedbackmay be logically utilized to stop insertion of the instrument at or nearthe left wall of the left atrium, or within the bends of the pulmonaryveins as they narrow away from the funnels of the left atrium.

A number of references have reported methods for determining contactbetween medical device instrumentation and tissue. For example, U.S.Pat. Nos. 5,935,079; 5,891,095; 5,836,990; 5,836,874; 5,673,704;5,662,108; 5,469,857; 5,447,529; 5,341,807; 5,078,714; and CanadianPatent Application 2,285,342 disclose various aspects of determiningelectrode-tissue contact by measuring changes in impedance between aninstrument electrode and a reference electrode. In an embodiment of thesubject invention wherein the instrument comprises suitably positionedelectrodes, techniques such as those disclosed in the art may beutilized. Other preferred embodiments of contact sensing means aredescribed in reference to FIGS. 151-157.

Referring to FIG. 151, an instrument (518) operated by an instrumentdriver and a closed-loop control system incorporating a localizationtechnology to measure actual instrument position is depicted. When theinstrument tip is driven through a range of motion, such as + pitch to −pitch, then back to neutral and + yaw to − yaw, at some cyclic interval,loads encountered by tissue structure contact, as opposed to free cavityspace in blood, for example, will tend to increase the error detectedbetween the measured tip position determined by the localization system,and the predicted tip location, determined via the inverse kinematics ofthe instrument structure. Other cyclic patterns of motion may also beutilized, such as repeated spiral motion, circular motion, etc.Depending upon the experimentally determined systematic error betweenthe predicted and measured tip locations in free space given aparticular instrument structure, a threshold may be utilized, beyondwhich error is considered an indicator of tissue contact. Depending uponthe cyclic motion pattern selected, the direction of contact between theinstrument and another object may also be detected by observing thedirectionality of error between predicted and measured instrumentposition.

Referring to FIG. 152, a distal tip of an instrument (519) is depictedhaving two vibratory devices (520). In one embodiment, one device is avibratory transmitter, such as a piezoelectric crystal adjacent amembrane, and the other device is a vibratory receiver comprising, forexample, a membrane adjacent another piezoelectric crystal. In anotherembodiment, both devices, a single device, or more than two devices maycomprise both transmitters and receivers. In free cavity space, theinstrument will vibrate more freely than it will when in mechanicalcontact with a tissue structure, and in this embodiment, the differenceis detected and logically interpreted as a tissue structure contactindicator.

Referring to FIGS. 153-155, another embodiment of a tissue contactsensing means is depicted wherein impedance monitoring through multiplepaths at multiple frequencies may be utilized as an indicator of tissuecontact. Conductivity measured through blood varies relatively littlewith frequency modulation, whereas conductivity does vary moresignificantly with frequency modulation when measured through a tissuestructure. By quickly switching frequencies and taking measurements atvarious frequencies, using, for example, a microprocessor, one can makea determination regarding contact with tissue or not based upon theassociated modulation in conductivity or impedance.

Such a technique may be combined with conductivity path modulation.Conventionally, impedance is measured between an instrument tipelectrode and a dispersive ground mounted, for example, upon the skin ofa patient's back. With such a configuration, conductivity increases, andimpedance decreases, when the instrument is in contact with, forexample, the heart wall. Another measurement path of interest isconductivity between an instrument tip electrode and another electrodeinside of the same chamber, but at a more proximal instrument location.As blood is relatively highly conductive, conductivity will be at amaximum when the tip electrode is not in contact with tissue, and willdecrease when the tip electrode touches a tissue wall, resulting inobscuring at least a portion of the tip electrode. Indeed, previousstudies have shown conductivity or impedance measurements take with sucha configuration can be utilized to predict contact before it actuallyoccurs, and that depth of tip electrode penetration may also bepredicted given the relationship between conductivity and obstruction ofthe tip electrode by tissue.

FIG. 153 depicts a further embodiment of an instrument (522) having adistal tip configured to facilitate such functionality. The instrument(522) has a tip electrode (523) disposed distally, and four electrodes(524 a-d) disposed more proximally at corner positions to facilitatecontact with tissue structures as the instrument (522) is positionedadjacent a tissue structure in a near parallel or tangential manner.FIG. 154 depicts the instrument (522) adjacent a tissue structure (523)with reference to a dispersive patch electrode (524) located upon theskin of a patient's back. With such a configuration, impedance may bemonitored between any pair of electrodes, with various frequencies, toprovide a configuration combining not only frequency modulation todetect tissue-electrode contact, but also conductivity comparison pathmodulation to detect tissue-electrode contact.

Referring to FIG. 155, a schematic is depicted for utilizing fastswitching hardware, such as microprocessors, to collect data with eachof the pertinent combinations. Each cycle of acquisition through thevarious combinations yields impedance difference monitoring based uponpath switching and frequency switching, which may be compiled andlogically associated with determinations of tissue contact or not, andeven the location of the instrument which is predicted to be in contactwith tissue. Many other variations of electrode arrays may be utilizedin addition to the configuration depicted in FIG. 153, and frequency maybe modulated between more than three frequencies, as depicted in FIG.155, to produce additional data for each combination acquisition cycle.

FIGS. 156 and 157 depict another embodiment of a means for detectingcontact between an instrument electrode and a tissue structure, such asa cardiac wall. The electrocardiogram (“ECG”) signal acquired by aninstrument electrode positioned in free blood in the heart shows adiscernable signal, but from a signal processing perspective, is lesssharp and lower in amplitude due to the attenuation of high frequencysignal content, as compared with similar signals detected when theelectrode is in contact with a cardiac wall. When the ECG signal isdifferentiated with respect to time, the resulting differentiated signalhas higher amplitude when the electrode is in contact, as compared witha slower-rising curve for a not-in-contact scenario. In one embodiment,a microcontroller or digital signal processor (“DSP”) is utilized toperform sampling, differentiation, and analysis of acquired ECGwaveforms. In another embodiment, the shape of incoming ECG waveforms ismonitored to detect not only contact, but proximity to contact as thewaveform shape changes with proximity to the pertinent tissue structure.

Referring to FIG. 157, similar signal processing means are utilized tocompare an intracardiac ECG signal (527) with a body surface ECG signal(528), which essentially represents a superposition of the various ECGwaveforms from subportions of the heart. The fit between theintracardiac ECG signal is compared with the body surface ECG signal todetermine whether the intracardiac ECG signal does indeed appear to be aportion of the combined signal represented by the body surface ECGsignal. If the superposition match does not meet an experimentallydetermined threshold, the result is logically related to a state ofnon-contact between the intracardiac electrode and the heart wall tissuestructures.

When the intracardiac electrode is in contact with a particular wall ofthe heart, the intracardiac ECG signal is crisp, detailed, and fits wellinto a portion of the superimposed combined body surface ECG signal, asdepicted in FIG. 157. In another embodiment, the body surface ECG signalmay be split into, for example, four subportions, each of which may becompared in a similar manner to the intracardiac ECG signal for adetermination of not only contact, but also a confirmation of positionwithin the heart as associated with the four subportions. For example,the body surface ECG signal may be subdivided into four portionsrepresentative of the four chambers of the heart, or even four portionsof the same chamber.

In a generic form, the aforementioned “master following mode” may belogically configured to follow directly each command as it comes throughthe control system from the master input device. In one closed loopcontrol embodiment, however, a logic layer is configured to interpretdata incoming from a master input device and a localization system inlight of the integrated tissue structure model and certain systemsettings information pertinent to the particular procedure at hand, tomake modifications to commands forwarded to the master following andsubsequent main servo loop controls logic, resulting in movements of thephysical instrument.

Referring to FIGS. 158A-160, some relatively simplistic examplesillustrate challenges addressed by interpreted master following. Theexemplary instrument embodiment depicted in each of these figurescomprises a localization device and a contact sensing device. Manycombinations or instrument componentry may be utilized with aninterpreted master following logic layer to provide an operator withenhanced navigation functionality, depending upon the functionalobjectives.

As shown in FIGS. 158A-D, an instrument (530) has a distal end carryinga localization device (532) is positioned adjacent an irregular tissuewall which is represented in the system's visualization and controlsystems by a preferably three-dimensional tissue structure modelacquired utilizing one of the aforementioned modalities. Supposing thatthe operator's objective is to move the instrument distal tip asindicated in FIGS. 158A-D, an operator's preferred movement path dependsupon his preferred action in between the two locations. For example, ifthe operator merely wishes to touch the instrument (530) to the tissuewall in each location without contacting any tissue in between, theoperator may prefer a path of efficiency (531) around the irregularityin the tissue structure, such as that depicted by a dashed line.Following this path, the operator may drive the instrument between therespective positions/locations.

Additionally or alternately, the operator may wish to lightly touch theinstrument (530) against the tissue structure and keep the instrument incontact as the instrument is driven between the locations depicted inFIG. 159A-D via a series of hops between the two locations, rather thana constant dragging type of contact as described in the aforementionedembodiment. Further, in another embodiment, as depicted in FIG. 160A-D,the operator may wish to move the instrument between positions, whilemaintaining the instrument substantially normal to the tissue structurewall, perhaps due to the preferred orientation of a distal instrumentfeature, e.g., an electrode.

In addition, the operator may wish to have safety functionality builtinto the controls logic to, for example, prevent the instrument fromdamaging the subject tissue structures by excessively dragging along thetissue with an excessive load, overloading or overstressing a particularportion of a tissue structure with a concentrated load, or occupying aregion that may cause tissue damage, such as an active valve entrance.

Such operator objectives are addressed in various embodiments of aninterpreted master following logic layer interposed into the controlslogic. In one embodiment, interpreted master following interpretscommands that would normally lead to dragging along the tissue structuresurface as commands to execute a succession of smaller “hops” to andfrom the tissue structure surface, while logging each contact as a newpoint to add to the tissue structure surface model. Hops are preferablyexecuted by backing the instrument out the same trajectory it came intocontact with the tissue structure, then moving normally along the wallper the tissue structure model, and re-approaching with a similartrajectory. In addition to saving to memory each new XYZ surface point,in one embodiment, the system saves the trajectory of the instrumentwith which the contact was made by saving the localization orientationdata and control element tension commands to allow the operator tore-execute the same trajectory at a later time if so desired. By savingthe trajectories and new points of contact confirmation, a more detailedcontour map is formed from the tissue structure model, which may beutilized in the procedure and continually enhanced. The length of eachhop may be configured, as well as the length of non-contact distance inbetween each hop contact.

In one embodiment, interpreted master following performs a variety ofsafety checking steps to ensure that the operator does not accidentallydamage the subject tissue structure by driving into it or through itwith the instrument. For example, the controls logic may be configuredto disallow driving of the instrument beyond or into the subject tissuestructure, as determined utilizing a tissue structure model withlocalization data and/or contact sensing. Such a mode may be manuallyoverridden with an operator command in certain scenarios, for example,in order to purposefully puncture a tissue wall such as the septum atthe location of the fossa ovalis. In one embodiment, the controls logicmay be configured to prevent instrument electrode activation while theoperator is attempting to move the instrument, or may attempt to preventelectrode activation in the same location for more than a predeterminedtime or amount of energy delivered.

In another embodiment, interpreted master following assists the operatorin automating various clinical procedures. For example, where theinstrument comprises a distal ablation electrode, the controls may beconfigured to automatically fit a circular ablation pattern throughthree contact points selected by the operator. Further, an operator mayselect a hopping, intermittent electrode burning pattern toautomatically apply has he merely moves the master input devicelinearly. Haptics functionality may be utilized to provide the operatorwith various feedback to assist in clinical procedures. For example, ahaptic “groove” may be created along the insertion axis of theinstrument to assist the operator in driving the instrument with themaster input device. Further, previously selected points of desiredcontact may be haptically turned in to “gravity wells” to assist theoperator in directing the instrument to such locations.

A control system embodiment, such as described above, facilitatesprecision steerability of a catheter-based instrument in order toconduct a medical procedure. As an exemplary application, a myocardialablation procedure to address atrial fibrillation will now be describedwith reference to FIGS. 161-174.

Referring to FIG. 161, a standard atrial approach is depicted with arobotically controlled guide catheter instrument (534) and sheathinstrument (535) passing through the inferior vena cava and into theright atrium. Referring to FIG. 162, an imaging device, such as anintracardiac echo (“ICE”) sonography catheter (536), is forwarded intothe right atrium to provide a field of view upon the interatrial septum.The guide instrument is driven to the septum wall, as shown in FIG. 163.Referring to FIGS. 164 and 165, the septum (537) may be crossed using aconventional technique of first puncturing the fossa ovalis locationwith a sharpened device (538), such as a needle or wire, passed throughthe working lumen of the guide instrument (534), then passing a dilator(539) over the sharpened device and withdrawing the sharpened device toleave the dilator (539), over which the guide instrument (534) may beadvanced, as shown in FIG. 166. It may be desirable in some embodimentsto pass an instrument arrangement through the working lumen of the guideinstrument comprising a needle positioned coaxially within a dilator, asis well known in conventional (i.e., non-robotic) septum crossingtechniques.

As shown in FIG. 167, subsequent to passing the guide instrument (534)across the septum (537), the guide instrument (534) may be utilized as adilator to insert the sheath instrument (535) across the septum (537),thereby providing both instruments (534, 535) access and/or a view intothe left atrium. It may be desirable to anchor the sheath instrument(535) in place just across the septum (537). For example, as shown inFIG. 168, an expanding structure such as a conventional balloon anchor(540) may be employed. As shown in FIG. 169, the guide instrument (534)may then be used to navigate inside the left atrium.

In one embodiment, a radio frequency (RF) ablation system is used withthe robotic catheter system to supply energy to perform myocardialtissue ablation procedures in order block undesirable conductionpathways within the wall of the left atrium and adjoining vessels (e.g.,pulmonary vein). By way of illustration, FIG. 170 depicts a system levelview of such arrangement, including an operator control station (2), acomputer (6), an instrument driver (16), a RF ablation energy controlunit (541), a guide instrument (543) and a working instrument (547).

In one embodiment, shown in FIG. 171, a robotically controlled guideinstrument (543), which may have an outer diameter of about 7 French,comprises an integrated ablation distal tip, and is passed through asheath instrument (535). In another embodiment, shown in FIG. 172, aworking instrument (547), in this instance an “off the shelf” ablationcatheter such as that sold under the trade name Blazer II™ CardiacAblation Catheter by Boston Scientific Corporation, which may have anouter diameter of about 7 French, is passed through the working lumen ofthe guide instrument (534), which itself is passed through a sheathinstrument (535). In such embodiments, the RF power may be supplieddirectly from the RF generator to the ablation catheter handle.Alternatively, the power supply may be coupled to the ablation cathetervia a controller integrated with the robotic guide instrument in orderto provide addition safety features, e.g., automatic power shut-offunder defined circumstances. In such embodiments, only a small portionof the ablation catheter need be protruded beyond the distal tip of theguide instrument to expose the ablation electrodes, and the steeringfeatures which may be integrated into the “off the shelf” ablationcatheter may not be needed as a result of the precision steerabilityprovided by the robotically-controlled instrumentation through which theablation catheter is coaxially positioned. Alternatively, a greaterportion of the ablation catheter may be protruded beyond the distal tipof the guide instrument, preferably with the guide instrument held in aconstant position by the system, and the manual steering functionalityof the “off the shelf” ablation catheter may be utilized to place thedistal portion of such device in a desired location, utilizing feedbackto the operator from fluoroscopy, ultrasound, localization, or otherreal-time or near real-time systems. It will be appreciated by thoseskilled in the art that many of types of other ablation catheters orother working instruments may be passed through the working lumen of theguide instrument (534).

The precision provided by a system comprising a robotic guide instrumentwith an ablation catheter positioned coaxially within the robotic guideinstrument facilitates precision mapping and creation of transmurallesions. In the right heart, without transseptal crossing, atrialflutter may be addressed by actively driving the distal tip of theablation catheter to the lower right atrium. The right atrial isthmusmay be contacted and ablated, along with the tricuspid annulus down tothe junction of the right atrium and the inferior vena cava. Long linearlesions may be created through inputs to the master input device invarious locations, such as the “intercavalline” between the superiorvena cava and the inferior vena cava, or the “septal line” from thesuperior vena cava to the fossa ovalis, and then from the fossa ovalisdown to the inferior vena cava. “Lasso” type ablation catheters may bedriven using the subject robotic instrument system, to isolate pulmonaryveins in the left heart, or conduct a segmental pulmonary veinisolation, wherein a subset of the electrodes positioned about the“Lasso” device are utilized to create ablation lesions. The procedureknown as “Left Atrial Catheter Ablation” or “LACA”, developed byclinicians such as Pappone and Morady, may be facilitated using thesubject system. LACA, which may involve large ablations to isolate theright superior pulmonary vein and right inferior pulmonary vein, alongwith ablative isolation of the left superior pulmonary vein and leftinferior pulmonary vein, a connecting ablation between theaforementioned lesions (“roofline” ablation), and a left atrial isthmuslinear ablation from the left inferior pulmonary vein to the mitralvalve annulus, may be addressed utilizing the robotic precision of thesubject system. Ablation targets such as the right inferior pulmonaryvein and the ridge between the left superior pulmonary vein and the leftinferior pulmonary vein may be particularly difficult without theprecision of the subject system.

There are many well-known diagnostic or therapeutic distal end electrodeconfigurations of working instruments that may used in conjunction withthe guide instrument (534), such as those shown by way of non-limitingexamples in FIGS. 173A-D. In these examples, electrodes are located atthe distal ends of a working instrument (547) that is coaxially passedthrough a robotically controlled guide instrument (543) and sheathinstrument (535). For example, FIG. 173A illustrates one embodiment of aguide instrument with a Y-split end wherein a distal end electrode (600,602) is located on the face each of the split ends. FIG. 173Billustrates one embodiment of a guide instrument wherein two electrodes(610) are radially located at two locations at the distal tip of theinstrument. FIG. 173C illustrates another embodiment of an instrumentwherein a single electrode (608) is located over the distal tip itself.The example in FIG. 173D illustrates a working instrument where anelectrode (610) is located on a side surface at the distal tip.

Other tip options include non-contact means such as microwave orultrasound energy as illustrated with an arrow emitted from distal tipelement (612) in FIG. 174A, optical laser energy as indicated withmultiple arrows emitted from distal tip element (614) in FIG. 174B, apenetrating electrode or chemical/drug injection needle (616) in FIG.174C, or mechanical grasper (618) in FIG. 174D.

In another embodiment, the instrument may be navigated by “directvisualization” utilizing conventional fiberscope or CCD camera devices,preferably disposed within a distally-positioned viewing ballooncontaining a substantially clear fluid such as saline when in a bloodenvironment. In yet another embodiment, an infrared visualizationtechnology, such as those available from CardioOptics, Inc. ofWilmington, Mass., may be coupled to the instrument to provide directvisualization through a blood or similar medium without a viewingballoon or similar structure. In another embodiment wherein theinstrument is navigated in a non-blood space, a viewing balloon need notbe positioned to protect the camera device, and the camera lens or imageintake may be positioned at the distal tip of the instrument. Whetherthe direct visualization device is assisted by a balloon-likevisualization structure or not, the device preferably is coupled to theinstrument either by insertion through the working lumen of anembodiment of the instrument, or integrated into one of the wallscomprising the elongate instrument.

Conventional sensors may be disposed at and/or around the distal tip ofthe instrument, such as those which comprise strain gages and/orpiezoelectric crystals. Also, more than one localization device may becoupled to the instrument along different positions of the instrument toallow for more complex monitoring of the position of the instrument.Such additional information may be utilized to help compensate for bodymovement or respiratory cycle related movement of tissues relative to abase coordinate system.

In still another embodiment of the tissue structure model acquisitionmodalities described above, including a contact sensor, the instrumentmay merely be driven around, in a planned fashion, or even at random,within a cavity to collect and store all points of contact to develop athree-dimensional model of the tissue structures. In a relatedembodiment, a rough model acquired utilizing a conventional imagingmodality such as ultrasound or fluoroscopy may be utilized as a startingpoint, and then additional points added, particularly at points ofinterest, such as pulmonary vein and valve locations within the leftatrium, utilizing a “tapping around” pattern with contact sensing togather more points and refine the model.

As described above in reference to FIG. 113, in one embodiment,visualization software provides an operator at an operator controlstation (2), such as that depicted in FIG. 1, with a digitized“dashboard” or “windshield” display to enhance instinctive drivabilityof the pertinent instrumentation within the pertinent tissue structures.

It may be useful to present the operator with one or more views ofvarious graphical objects in an overlaid format, to facilitate theuser's comprehension of relative positioning of the various structures.For example, it may be useful to overlay a real-time fluoroscopy imagewith digitally-generated “cartoon” representations of the predictedlocations of various structures or images. Indeed, in one embodiment, areal-time or updated-as-acquired fluoroscopy image including afluoroscopic representation of the location of an instrument may beoverlaid with a real-time representation of where the computerizedsystem expects the instrument to be relative to the surrounding anatomy.In a related variation, updated images from other associated modalities,such as intracardiac echocardiography ultrasound (ICE), may also beoverlaid onto the display with the fluoro and instrument “cartoon”image, to provide the operator with an information-rich rendering on onedisplay.

Referring to FIG. 175, a systemic view configured to produce such anoverlaid image is depicted. As shown in FIG. 175, a conventionalfluoroscopy system (330) outputs an electronic image in formats such asthose known as “S-video” or “analog high-resolution video”. In imageoutput interface (332) of a fluoroscopy system (330) may be connected toan input interface of a computer (342) based image acquisition device,such as those known as “frame grabber” (334) image acquisition cards, tofacilitate intake of the video signal from the fluoroscopy system (330)into the frame grabber (334), which may be configured to produce bitmap(“BMP”) digital image data, generally comprising a series of Cartesianpixel coordinates and associated grayscale or color values whichtogether may be depicted as an image. The bitmap data may then beprocessed utilizing computer graphics rendering algorithms, such asthose available in conventional OpenGL graphics libraries (336). Insummary, conventional OpenGL functionality enables a programmer oroperator to define object positions, textures, sizes, lights, andcameras to produce three-dimensional renderings on a two-dimensionaldisplay. The process of building a scene, describing objects, lights,and camera position, and using OpenGL functionality to turn such aconfiguration into a two-dimensional image for display is known incomputer graphics as rendering. The description of objects may behandled by forming a mesh of triangles, which conventional graphicscards are configured to interpret and output displayable two-dimensionalimages for a conventional display or computer monitor, as would beapparent to one skilled in the art. Thus the OpenGL software (336) maybe configured to send rendering data to the graphics card (338) in thesystem depicted in FIG. 175, which may then be output to a conventionaldisplay (340).

In one embodiment, a triangular mesh generated with OpenGL software toform a cartoon-like rendering of an elongate instrument moving in spaceaccording to movements from, for example, a master following modeoperational state, may be directed to a computer graphics card, alongwith frame grabber and OpenGL processed fluoroscopic video data. Thus amoving cartoon-like image of an elongate instrument would bedisplayable. To project updated fluoroscopic image data onto aflat-appearing surface in the same display, a plane object,conventionally rendered by defining two triangles, may be created, andthe updated fluoroscopic image data may be texture mapped onto theplane. Thus the cartoon-like image of the elongate instrument may beoverlaid with the plane object upon which the updated fluoroscopic imagedata is texture mapped. Camera and light source positioning may bepre-selected, or selectable by the operator through the mouse or otherinput device, for example, to enable the operator to select desiredimage perspectives for his two-dimensional computer display. Theperspectives, which may be defined as origin position and vectorposition of the camera, may be selected to match with standard viewscoming from a fluoroscopy system, such as anterior/posterior and lateralviews of a patient lying on an operating table. When the elongateinstrument is visible in the fluoroscopy images, the fluoroscopy planeobject and cartoon instrument object may be registered with each otherby ensuring that the instrument depicted in the fluoroscopy plane linesup with the cartoon version of the instrument. In one embodiment,several perspectives are viewed while the cartoon object is moved usingan input device such as a mouse, until the cartoon instrument object isregistered with the fluoroscopic plane image of the instrument. Becauseboth the position of the cartoon object and fluoroscopic image objectmay be updated in real time, an operator, or the system automaticallythrough image processing of the overlaid image, may interpretsignificant depicted mismatch between the position of the instrumentcartoon and the instrument fluoroscopic image as contact with astructure that is inhibiting the normal predicted motion of theinstrument, error or malfunction in the instrument, or error ormalfunction in the predictive controls software underlying the depictedposition of the instrument cartoon.

Referring back to FIG. 175, other video signals (not shown) may bedirected to the image grabber (334), besides that of a fluoroscopysystem (330), simultaneously. For example, images from an intracardiacecho ultrasound (“ICE”) system, intravascular ultrasound (“IVUS”), orother system may be overlaid onto the same displayed imagesimultaneously. Further, additional objects besides a plane for texturemapping fluoroscopy or a elongate instrument cartoon object may beprocessed using OpenGL or other rendering software to add additionalobjects to the final display.

Referring to FIGS. 176 A-B and FIG. 177, one embodiment is illustratedwherein the elongate instrument is a robotic guide catheter, andfluoroscopy and ICE are utilized to visualize the cardiac and othersurrounding tissues, and instrument objects. Referring to FIG. 176A, afluoroscopy image has been texture mapped upon a plane configured tooccupy nearly the entire display area in the background. Visible in thefluoroscopy image as a dark elongate shadow is the actual position, fromfluoroscopy, of the guide catheter instrument relative to thesurrounding tissues. Overlaid in front of the fluoroscopy plane is acartoon rendering (white in color in FIGS. 176A-B) of the predicted, or“commanded”, guide catheter instrument position. Further overlaid infront of the fluoroscopy plane is a small cartoon object representingthe position of the ICE transducer, as well as another plane objectadjacent the ICE transducer cartoon object onto which the ICE image datais texture mapped by a technique similar to that with which thefluoroscopic images are texture mapped upon the background plane object.Further, mouse objects, software menu objects, and many other objectsmay be overlaid. FIG. 176B shows a similar view with the instrument in adifferent position. For illustrative purposes, FIGS. 176A-B depictmisalignment of the instrument position from the fluoroscopy object, ascompared with the instrument position from the cartoon object. Asdescribed above, the various objects may be registered to each other bymanually aligning cartoon objects with captured image objects inmultiple views until the various objects are aligned as desired. Imageprocessing of markers and shapes of various objects may be utilized toautomate portions of such a registration process.

Referring to FIG. 177, a schematic is depicted to illustrate how variousobjects, originating from actual medical images processed by framegrabber, originating from commanded instrument position control outputs,or originating from computer operating system visual objects, such asmouse, menu, or control panel objects, may be overlaid into the samedisplay.

In another embodiment, a preacquired image of pertinent tissue, such asa three-dimensional image of a heart, may be overlaid and registered toupdated images from real-time medical imaging modalities as well. Forexample, in one embodiment, a beating heart may be preoperatively imagedusing gated computed tomography (CT). The result of CT imaging may be astack of CT data slices. Utilizing either manual or automatedthresholding techniques, along with interpolation, smoothing, and/orother conventional image processing techniques available in softwarepackages such as that sold under the tradename Amira™ product availablefrom Mercury Computer Systems of Chelmsford, Mass., a triangular meshmay be constructed to represent a three-dimensional cartoon-like objectof the heart, saved, for example, as an object (“.obj”) file, and addedto the rendering as a heart object. The heart object may then beregistered as discussed above to other depicted images, such asfluoroscopy images, utilizing known tissue landmarks in multiple views,and contrast agent techniques to particularly see show certain tissuelandmarks, such as the outline of an aorta, ventricle, or left atrium.The cartoon heart object may be moved around, by mouse, for example,until it is appropriately registered in various views, such asanterior/posterior and lateral, with the other overlaid objects.

Referring to FIG. 178, a distributed system architecture embodiment isdepicted. A master control computer running a real-time operatingsystem, such as QNX, is connected to each of the other computers in thesystem by a 1 gigabit Ethernet “Real-time Network”, and also by a 100megabit Ethernet “System Network”, using a conventional high-speedswitch. This enables localized custom computing for various devices tobe pushed locally near the device, without the need for large cabling ora central computing machine. In one embodiment, the master controlcomputer may be powered by an Intel® Xeon® processor available fromIntel Corporation of Santa Clara, Calif., the visualization computerpowered by a personal computer (PC) with a high-end microprocessor basedon the Intel architecture running Windows XP and having multiple videocards and frame grabbers, the instrument driver and master input deviceCPUs being PC 104 or “EPIC” standard boards with two Ethernetconnections for the two networks. An additional master input device,touchscreen, and console may be configured into an addition operatorworkstation in a different location relative to the patient. The systemis very expandable—new devices may be plugged into the switch and placedonto either of the two networks. Referring to FIG. 178, two highresolution frame grabber boards (374) acquire images from two fluorodevices (or one in the case of single plane fluoro), which a nominalresolution frame grabber board (373) acquires images from anintracardiac echo system. Such image data may be utilized foroverlaying, etc, as described in reference to FIGS. 175-177, anddisplayed on a display, such as the #2 display, using a video card (372)of the visualization computer, as depicted. Heart monitor data, from asystem such as the Prucka CardioLab EP System distributed by GEHealthcare of Waukesha, Wis., may be directly channeled from video outports on the heart monitor device to one of the displays. Such data mayalso be acquired by a frame grabber. Similarly, electrophysiologicalmapping and treatment data and images from systems available fromdistributors such as Endocardial Solutions, Biosense Webster, Inc.,etc., may be directed as video to a monitor, or data to a dataacquisition board, data bus, or frame grabber. Preferably the mastercontrol computer has some interface connectivity with theelectrophysiology system as well to enable single master input devicedriving of such device, etc. Referring to FIG. 179, a depiction of thesoftware and hardware interaction is depicted. Essentially, the masterstate machine functionality of the master control system real-timeoperating system allows for very low latency control of processes usedto operate master input device algorithms and instrument driveralgorithms, such as those described in reference to the control systemsdescription above. Indeed, XPC may be utilized to develop algorithmcode, but preferably a universal modeling language such as IBM RationalRose from IBM Corporation of Armonk, N.Y., or Rhapsody of I-Logix ofAndover, Mass., is utilized to build code and documentation using agraphical interface. With the gigabit real-time network, in a matter of200-300 microseconds, the master input device or instrument driveralgorithms are able to communicate with FPGA driver code in theelectronics and hardware near the pertinent device to exchange newvalues, etc, and confirm that all is well from a safety perspective.This leaves approximately 700 microseconds for processing if a 1millisecond motor shutoff time is required if all is not well—and thisis easily achievable with the described architecture. The visualizationPC may be configured to cycle data from the master control computer at alower frequency, about 20 milliseconds. FIG. 180 illustrates thesoftware interaction of one embodiment.

Referring to FIG. 181, common features may be accessed by a console.Sheath control buttons for roll, bend, and insert, when depressed one ata time, cause the master input device to control roll of the sheath (inone embodiment, this meaning roll of the entire instrument driver) inone direction or another as directed by the master input device, +/−bending in one direction, and insertion of the sheath relative to theguide instrument. Instinctive control buttons determine whether the maindisplay is to synchronize master input device movement with 3-D images,such as CT images, or fluoro images. An auto retract button pulls in theguide instrument to a zero insertion point along the trajectory that itwas bent. A trackball and mouse select buttons may be used for somefeatures not accessed by a touch screen interface. Record featuresrecord a digital clip of video on a selected monitor for a preset periodof time, or acquire an image of the video on a selected monitor. Cameracontrols enable the operator to pan or zoom an image featured on adisplay.

Referring to FIGS. 182-186, a touchscreen interface provides a palatefor virtually unlimited control configuration in one embodiment of thepresent invention. Various embodiments of patient data setup, operatorpreset, data storage and retrieval, and operational procedure aspectsmay be coded into the touch screen interface for easy access during anoperation.

FIG. 183A illustrates an example touchscreen display for selecting aprocedure type. FIG. 183B illustrates a touchscreen wherein patient datacan be entered into the system with an onscreen QWERTY keyboard. FIG.184A illustrates a touchscreen wherein various system presets can beviewed and modified for the current procedure. FIG. 184B illustrates ashot of screen wherein the user presets may be saved. FIG. 184Cillustrates a screen fore entering a preset name. A screen formaintaining various system presets is displayed in FIG. 184D. FIG. 184Eillustrates a screenshot of the display when a preset is deleted. FIG.185A illustrates a screen for retrieving and maintaining patient data.FIG. 185B illustrates a screen wherein user data can be exported to orimported from a removable media such as a CD or DVD. A confirmationmessage relating to the loading of stored images is illustrated in FIG.185C. FIG. 185D shows a confirmation message relating to the deletion ofpatient data. FIG. 186A illustrates one example of the menu available toan operator during a procedure. A confirmation message relating to thetermination of a procedure is show in FIG. 186B. FIG. 186C illustratesthe message displayed during the registration process for a catheter.FIG. 186D illustrates a screen for catheter control and marking ofanatomical points of interests.

Referring to FIGS. 187A-191C, several embodiments of minimally invasiveinstruments and kits thereof which may be preferred for a cardiacablation procedure in accordance with the present invention aredepicted.

Referring to FIGS. 187A-188B, various aspects of one embodiment of asheath instrument (227) are depicted. The finished assembly of thedepicted embodiment preferably has an inner lumen of about 145 mils and158 mils (noncircular x-section, the former being the smaller innerlumen diameter (ID), the latter being the larger ID) which is configuredto fit the outer finish diameter, or (OD), of a guide instrument such asthat described in reference to FIGS. 189A-189C, which has an innerdiameter of approximately 8 French—a size configured to fit severalapproved off-the-shelf ablation catheters, as well as needle/dilatorsets such as those described below.

Referring to FIG. 187A, the depicted sheath instrument (227) embodimentcomprises a sheath catheter member (208) which is proximally coupled toa sheath instrument base (46) which is coupled to a control elementinterface assembly (147) and Luer assembly (225). The control elementinterface assembly (147), similar to those described in reference toFIGS. 103.5 and 103.6, for example, has a splined axle (157) configuredto interface with an instrument driver interface socket (not shown, seeitem (44) of FIG. 6, for example). The total working length of theportion of the catheter member (208) distal of the sheath instrumentbase (46) is approximately 78 centimeters in the depicted embodiment.Approximately 2.5 inches from the distal tip (237), a proximal ring(233) is integrated into the assembly to provide not only radio-opacityfor fluoroscopy, and also conductivity for a potential difference typelocalization integration as discussed above, but also for terminationand return of a proximal control element (not shown in FIG. 187A) which,in the depicted embodiment, is configured to extend from the one or morepulleys (not shown in FIG. 187A) associated with the manual adjustmentknob (229) to the proximal ring (233) and back to the one or morepulleys (not shown in FIG. 187A) associated with the manual adjustmentknob (229). Approximately 2 millimeters from the distal tip (237), adistal ring (231) is positioned to function similarly to the proximalring (233), but for a distal control element which, in the depictedembodiment, preferably is looped from the one or more pulleys (not shownin FIG. 187A) comprising the control element interface assembly (147),which is configured to be servo-robotically actuated from an instrumentdriver to which it may be coupled. The looping configuration of thecontrol elements preferably provides greater break strength, in therange of twice the break strength of a single strand of the same controlelement wire material under tension, because with the both-side-soldered(325) and looping configuration around the proximal (233) or distal(231) ring, as depicted in FIG. 187D, each of the two strands of thecontinuous control element is configured to share loads as separatetension elements. The portion approximately two inches proximal of thedistal ring (231) is configured to have relatively high, yetcontrollable flexibility, as controlled by catheter member reinforcingstructures or ribs discussed in reference to FIG. 187B.

Referring to FIG. 187B, a cross sectional view of a distal portion ofthis embodiment of a sheath instrument (227) depicted in FIG. 187A isdepicted. As shown in FIG. 187B, the assembly is created around amandrel (243) which is removed after assembly, which has arounded-cornered-square cross section having a maximum diameter (257) ofapproximately 158 mils. Several layers are formed over the mandrel(243), as described in reference to FIG. 187E, including an inner layer(249), a distal control element (239) liner set (247), a braided layer(251), structural rib elements (245), and an outer jacket layer (255).The structural rib elements (245) function like small beams integratedinto the walls of the construct and are configured to resist homogeneousomnidirectional cantilevered bending of the distal end of the sheath.

Referring to FIG. 187C, a cross sectional view of a more proximalportion of this embodiment of a sheath instrument (227) depicted in FIG.400A is depicted. The same mandrel (243) is utilized to construct theproximal portion, over which an inner layer (249) is placed, followed bya liner sets (247) for each of the subsequently introduced proximal anddistal control elements (241, 239), a braided layer (251), a secondbraided layer (254), and an outer jacket layer (253) different from theouter jacket layer (255) of the distal portion of the sheath instrument(227).

Referring to FIG. 187E, one embodiment of a method of constructing theembodiment depicted in FIGS. 187A-187D is illustrated as exemplary stepsdescribed in block A through L. The first step at block A comprisesplacing a nylon 12 jacket approximately 2-3 mils thick over the entirelength (proximal and distal) of the mandrel. Next at block B, polyimidetubes lined with polytetrafluoroethylene (PTFE) are stuffed withrectangular mandrels 4 mil by 12 mil. These small mandrels areplaceholders for the tension elements, to be installed later with thepertinent ring element to which they are pre-soldered. The polyimide,PTFE-lined, mandrels are heat shrink bonded to the nylon jacket,subsequent to which at block C, the proximal portion (proximal to theapproximately two-inch more flexible distal section in this embodiment)is braided with 1×3 mil rectangular wire at 75 ppi (picks per inch)diamond pattern; the braiding is loosened in pattern over the distalsection to 60 ppi. Next at block C+, the distal section is covered witha later-to-be-removed heat shrink tubing layer, subsequent to which atblock D, the entire length of the construct is braided again with thesame wire at a 40 ppi rate. Next at block E, a 3 mil thick nylon 12jacket is applied over the proximal portion (proximal of the subsequentposition of the proximal ring), and the structure is heat fused at blockF through a vertical heat shrinking device. Next at block G, the distalheat shrink (from block C+ is removed along with any materials over it,and the pre-soldered proximal ring with looped proximal control elementis installed at block H by pulling the small mandrels out andpushing/pulling the looped control element into the same positions, andsubsequently encapsulating the proximal ring into place with a smallcuff of nylon 12 material. Next at block I, rectangular reinforcing ribs(approximately 0.016×0.40 inches) are heat tacked into place along thesides of the portion of the sheath approximately two inches proximal tothe position of the distal ring, and subsequently at block J, alow-durometer jacket, preferably a Pebax resin with a 40 Shore Ddurometer hardness value, is heat fused over the portion of the sheathdistal to the proximal ring. Subsequently at block K, the distal ringand associated tension elements are installed similar to theinstallation of the proximal ring and tension elements, and at block L,a short (approximately 1-2 mm long in this embodiment) soft tip section,preferably 35 Shore D durometer hardness value, is heat welded to thedistal end, followed by installation of a Luer assembly proximally, andfinal assembly instrument base, including exposure of the two loopedcontrol elements through the wall of the proximal portion of thecatheter member, installation of termination balls, preferably bymechanical crimp, upon the proximal ends of the control elements, andwinding about the pertinent pulleys of the control element interfaceassembly and manual-knob-driven proximal element pulley.

Referring to FIGS. 188A-B, isometric views of the sheath instrument base(259) assembly are depicted to illustrate that the distal controlelement loop (239) in the embodiment depicted in FIGS. 187A-E may beservo robotically driven through a control element interface assembly(147) configured to interface with an instrument driver interface socket(not shown), while the proximal control element loop (241) may beactuated with a worm screw mechanism associated with a manual tensioningknob (229). FIG. 188B depicts an exploded view of the assembly of FIG.188A. With the top plate (267) removed from the sheath instrument base(259), where it is fastened with fasteners (269) such as screws whenfully assembled, the work gear (261) coupled to the manual tensioningknob (229) and the associated control element drive gear (263) andassociated control element pulley (265) is depicted. A track (235) isdepicted, formed in the sheath instrument base (259), to provide apathway for the proximal control element loop to exit the wall of theproximal catheter member and spool into the control element pulley(265).

FIGS. 189A-C illustrate one embodiment of a guide instrument (275)configured to coaxially interface with an embodiment of the sheathinstrument (227) depicted in FIGS. 187A-188B. The working length (277)of the depicted guide instrument catheter member (90) is about 92centimeters, the most distal 122 millimeters of which (273, 271) aresignificantly more flexible or bendable than the proximal portions. Thevery distal 2 mm (271) comprises a soft tapered distal tip of an evenmore pliable polymeric material. This embodiment of the guide instrumenthas four control elements fastened to a single distal ring (295) andconfigured to facilitate omnidirectional distal tip navigation from aproximal interface to a servo robotic instrument driver, such as thosedescribed above. A guide instrument base (141) and two associatedcontrol element interface assemblies (147) and axles (157) are depictedin a configuration similar to that described in reference to FIGS.103.1-103.6. In another embodiment, the guide instrument base (48) maycomprise a configuration such as that depicted in FIG. 6 and beconfigured for a four interface socket (44) instrument driver (16)configuration such as that depicted in FIG. 6.

Referring to FIG. 189B, a proximal cross section of the guide instrumentcatheter member (90) depicted in FIG. 189A is depicted. Starting with anapproximately circular mandrel (279) with a diameter of approximately 8French, an inner layer (281) of nylon may be formed, followed by a metalhypotube layer (283) friction fit onto the most proximal eight inches ofthe construct, the metal hypotube layer (283) being about 5 mils inthickness. A braid layer (285) is subsequently added, followed by asecond braiding layer (291) into which small mandrels (289) and liners(287) are woven, followed by installation of an outer jacket (293).Other details regarding this construction are described in reference toFIG. 189C.

Referring to FIG. 189C, steps for one method of constructing a guideinstrument (275) embodiment such as that depicted in FIG. 189A areillustrated. At block B, a 113 ID, 1170D (mils) thin nylon 12 jacket isplaced over an 8 French mandrel from block A. Then an approximately 8″long 5 mil thick metal hypotube is fit over that proximally with afriction fit at block C. The entire length is then braided with diamondpattern (same wire as with above sheath) at 70 ppi at block D. Then atblock E, another braid layer is installed at 20 ppi, into which is wovenfour 10 mil ID, 12 mil OD, PTFE-lined, polyimide tubes with 9.5 milPTFE-coated mandrels inside. A distal control ring is installed at blockF with four pre-soldered (with gold/tin) control elements or loops ofcontrol elements—which are fed into the positions of the small mandrelsas woven into the second layer of braid. At block G, a keying extrusionis placed proximally (but not over the distal 122 mm portion in thisembodiment). The guide instrument of this embodiment has a circularinner lumen and a substantially rectangular outer cross sectional shapefor keying with a coaxially-positioned sheath lumen such as thosedepicted in FIGS. 187B and 187C, to prevent relative rotation betweensuch sheath instrument and guide instrument when coaxially interfaced.The distal 12 mm section of the instrument gets a Pebax resin jacketwith a 40 Shore D durometer hardness value at block H. At block I, thedistal ring is encapsulated with a nylon 12 cuff and a 35 Shore Ddurometer hardness value soft distal tip is installed. The entireconstruct is heat shrunken at block J and pressed into a rectangularcross sectional mold to keep the keyed cross section in place (primarilyproximally, about the region of the metal hypotube layer). AT block K,the proximal pullwires are exposed for instrument base installation. ALuer assembly is added at block L and the proximal instrument base isinstalled at block M. The final construct of the depicted embodiment hasan inner diameter of approximately 8 French and an outer diameter ofapproximately 152 mils long axis, and 138 mils short axis.

Although both the guide and sheath instruments described in reference toFIGS. 187A-189C utilize braiding for added torquability and kinkresistance, spiral winds or spine constructs, such as those describedabove in reference to FIGS. 25-32 may also be utilized or server asimilar purpose.

Referring to FIGS. 190A-C, various views of one embodiment of a dilatorcompatible with the guide and sheath instruments described in referenceto FIGS. 187A-189C are depicted. The depicted dilator embodiment (297)may be created by placing a thin polyimide liner (301) in FIG. 190C,which may be coated on the interior, mandrel-facing, lumen with alubricious surface such as PTFE, over a PTFE-coated mandrel (not shown),then butt-welding a relatively long section of relatively rigidpolymeric material, such as a Pebax resin having a 72 Shore D durometerhardness value, to a relatively short distal section (311) in FIG. 190Aof relatively flexible polymeric material, such as 45 durometer Pebax,to form a main tubular body (299) which is more flexible distally thanproximally. Proximally a Luer assembly (305) and hemostasis valve (307)are installed. A small platinum/iridium radio-opaque marker band (303)is installed distally, adjacent to which a 9-degree tapered end iscreated with a glass mold for tissue dilation at the distal tip of thedilator instrument embodiment (297). The inner lumen (309) diameter atthe distal tip is configured to be very close to the outer diameter ofthe needle for which the dilator is configured to be used, while theouter diameter of the dilator is configured to fit within the innerdiameter of the guide instrument with which is it configured to beutilized. In other words, each of the needle, dilator, guide, and sheathinstruments preferably are configured for coaxial interfacing during aprocedure.

Referring to FIGS. 191A-191C, various views of one embodiment of aneedle compatible with the guide, sheath, and dilator instrumentsdescribed in reference to FIGS. 187A-190C are depicted, wherein aflexible section near the distal tip facilitates passage of the needlearound tight turns within a constraining lumen. An instrument setcomprising a coaxial coupling of a sheath instrument, a guideinstrument, a dilator instrument, and a needle instrument such as thosedescribed herein may be utilized to conduct a trans-septal puncture, asdescribed above in reference to FIGS. 163-167. Subsequently, the needleand dilator may be withdrawn, and an ablation or mapping catheterinserted down the working lumen of the guide catheter to conduct arobotically-controlled ablation or mapping procedure, as described abovein reference to FIGS. 167-172, within the chambers of the heart.

At the heart of the needle embodiment (313) depicted in FIGS. 191A-C isan intermediate section (319) of greater flexibility positionedproximally adjacent the distal non-coring needle point (318) of theneedle to enable the distal end (318, 320) of the needle to navigatearound small radius of curvature turns more easily than a conventionalneedle without the highly flexible section (319). The distal end (318,320) preferably is soldered with gold or platinum material to provideradio-opacity, thereby facilitating placement and positioning of thedistal end (318, 320) during a procedure. Proximal of the highlyflexible section (319), the proximal needle shaft (321) preferablycomprises stainless steel, and may be coupled to a pin vise (317).Proximally a Luer assembly (315) is installed upon the proximal needleshaft (321).

Referring to FIGS. 191B and 191C, two embodiments of the distal end(318, 320) and highly flexible section (319) are depicted in close upcross sectional view. In both embodiments, to prevent kinking, aprefabricated construct of polyimide and wire (322), the wire embeddedinto the polyimide in a braided or spiral wound pattern, is placed overthe highly flexible section (319). Proximal of the highly flexiblesection (319), both proximal needle shaft sections (321) preferablycomprise stainless steel. In the embodiment of FIG. 191C, the distalsection (320) comprises stainless steel, while the section in betweenthe distal section (320) and proximal section (321) which lies at thecenter of the highly flexible section (319), also termed the flexibleshaft portion (326), comprises nitinol. In the embodiment of FIG. 191D,the flexible shaft portion (326) and distal end section (320) comprisethe same nitinol tube member. The depicted junctions between nitinoltubing and stainless steel tubing preferably are held together with anadhesive (323) such as epoxy, as depicted in FIGS. 191B-C. The distalsection of the embodiment depicted in FIG. 404C may be created by merelynecking down the anti-kink metal-reinforced polyimide layer and creatinga needle tip (318). With nitinol extending distally from the proximalneedle shaft section (321), the entire distal portion of the embodimentof FIG. 191C is highly flexible—facilitating tight turn radii throughtortuous paths of constraining lumens such as catheters or vessels. Theembodiment of FIG. 191C, also having a highly flexible section (319) duein part to a nitinol flexible shaft portion (326), has a less flexibledistal end (318, 320), complements of the stainless steel materialcomprising it, which may be desirable when the more dramatic flexibilityof the embodiment of FIG. 191C is not desired.

Many tools and sets of tools and instruments may be controllablydelivered and actuated with the help of a guide, or guide+sheathinstrument combination similar to those described in reference to theneedle/dilator/guide/sheath instrument arrangement disclosed above. Forexample, in some embodiments of the present invention, aremotely-actuated grasper, such as those available from IntuitiveSurgical, Inc. of Sunnyvale, Calif., or as described in U.S. patentapplication Ser. No. 10/011,371 to endoVia Medical, Inc., may be used inconcert with a remotely steerable guide instrument system sizedappropriately for the particular application. In other embodiments, aremotely steerable guide instrument system such as those describedherein may be utilized to place a guidewire, inject with a needle geneor cell therapy into the heart wall, the parenchyma of an organ, etc. Inyet other embodiments, a remotely steerable guide instrument system suchas those described herein may be utilized to carry a camera and/or aradiation source (such as a light, or infrared source for cameras suchas those available from CardioOptics, Inc.). In still other embodiments,a remotely steerable guide instrument system such as those describedherein may be utilized to carry a cryo-ablation system or laser ablationsystem to a precise location adjacent an organ, inside the heart, etc.In still further embodiments, a remotely steerable guide instrumentsystem such as those described herein may be utilized to place a pacinglead into the coronary sinus, or place a sensor within the heart orvessels for monitoring, for example, pressure within the left ventricle.Such pressure monitoring may be used, for example, to closely watchheart failure patients and adjust medicine, diuretics, fluid intake,etc. In yet further embodiments, a remotely steerable guide instrumentsystem such as those described herein may be utilized to deploy anexpandable or expanded medical device, such as a stent or stent graft,into a vessel or other lumen with a high degree of precision andvisualization. In other embodiments, multiple remotely steerable guideinstrument systems such as those described herein may be utilized in aprocedure. For example, one guide instrument could be used for preciselypositioning a camera and light source while another guide instrumentcould be used for precisely positioning an interventional instrumentsuch as a grasper, ablation tool, injection needle, etc. Still furtherembodiments may include tools including but not limited to: graspers, 2degree of freedom (DOF) articulating guidewires (roll+bend), biopsyforceps, high energy directed ultrasound probes, biopsy needles, lasers,aspiration needles, ultraviolet (UV) light sources, guides for pacing orother lead delivery, needles for drug delivery and biopsy, scissors,radio frequency (RF) ablation probes/tools/needles, clamp and stitchtools, cryo ablation devices, pledget placement devices, ultrasoundablation tools, clip delivery tools, ultrasound tissue welding probes,flow transducers, RF tissue welding tools, and pressure transducers. Itshould be appreciated that a complete embodiment of the invention mayincorporate any more such tool or instrument.

Referring to FIGS. 192A-192Q, various embodiments of the invention mayemploy many different tools that are positioned in the working lumen ofa guide instrument (18), which is depicted as coaxially coupled to asheath instrument (30), of a robotic catheter system. Tools such as theKittner absorbent probe (800) of FIG. 192A, the Maryland dissector (801)of FIG. 192B, the needle holder/grasper (802) of FIG. 192C, themulti-fire coil tacker (803) of FIG. 192D, the stapler or clip applier(804) of FIG. 192E, configured to apply clips or staples (805), thecautery probe (806) of FIG. 192F, the cautery hook (807) of FIG. 192G,the shovel/spatula cautery probe (808) of FIG. 192H, the serratedgraspers (809) of FIG. 192I, the tethered graspers (810) of FIG. 192J,the helical retraction probe (811) of FIG. 192K, the scalpel (812) ofFIG. 192L, the basket capture tool (813) of FIG. 192M, the curvedscissor (814) of FIG. 192N, the straight scissor (815) of FIG. 192O, theneedle (816) of FIG. 192P, and the irrigation tool (817) of FIG. 192Qmay be operated or positioned with an independent tool actuationthrough, for example, a separate tension member coaxially positionedalong with or through the tool. For example, graspers may bespring-biased to stay open or stay closed—and may be forcibly opened orclosed with a tension member specifically adapted to cause suchactuation proximally.

With each use of a guide instrument (18), a sheath instrument (30) mayalso be used to provide greater functionality and load capability. FIG.193 depicts an embodiment of a control/actuation configuration of aninstrument assembly comprising a guide instrument (18) and sheathinstrument (30), each of which are operated instrument by an instrumentdriver (16). FIG. 193 depicts an embodiment wherein a sheath instrument(30) having a sheath instrument base (46) configured with four controlelement interface assemblies (132) independently actuatable from theinstrument driver (16) is paired with a guide instrument (30) having aguide instrument base (48) configured with four control elementinterface assemblies (132) independently actuatable from the instrumentdriver (16). The working lumen access port (845) and working lumendistal aperture or port (846) are also illustrated. Such an embodimentmay be configured such that the sheath instrument (30) has steerabilityby four independent tension elements, while the guide instrument hassteerability by four independent tension elements—i.e., all eighttension elements may be independently and simultaneously controlled bythe same instrument driver (16).

FIG. 193 also depicts an embodiment wherein a tool may be positionedinto the working lumen access port (845) and electromechanicallyactuated through the use of an electromechanical actuator fitting (847)which may be coupled to the guide instrument base (48), for example, andalso operably coupled to a tool which may be positioned into the workinglumen of the guide instrument (18). As described above, FIG. 193illustrates an embodiment capable of four tension element sheathinstrument (30) control and four tension element guide instrument (18)control, as well as actuation or positioning of a tool by virtue of itsmechanical association with the depicted electromechanical actuatorfitting (847). Thus the depicted embodiment is capable of eightindependent and simultaneous tensioning or steering actuations, as wellas one tool actuation simultaneously and independently, all from thesame instrument driver, as depicted. For example, a tool, such as atethered grasper, may be actuated with a tension element operablycoupled to the actuator fitting (847) in a similar manner that thetension elements described above are operably coupled to the controlelement interface assemblies (132). In other embodiments, lead screws,racks and pinions, and other mechanical couplings are desirable foroperating or controlling a tool. In other embodiments withoutelectromechanical tool actuation, or in embodiments where additionalactuation is desired besides electromechanical, tools may be actuatedmanually by the operator at a position proximal to the working lumenaccess port (845).

Referring to FIGS. 194C, D, F, and G, embodiments wherein one or morepairings of sheath instrument (30) and guide instrument (18) may bepositioned through a larger diameter instrument which may have one ormore working lumens and be configured to carry one or more image capturedevices, an imaging radiation source, and an irrigation port, forexample. Referring to FIG. 194C, a sheath (30) and guide (18) instrumentpairing are positioned within a first working lumen (858) defined by alarger or “parent” endoscopic instrument (820), which carries first(853) and second (860) image capture devices, which may be utilized forstereoscopic imaging, an imaging radiation source (854), such a lightradiation or infrared radiation source, and an irrigation port (861).Each of the image capture devices may, for example, comprise a lens, aCCD chip, optical fiber, or an infrared or other radiation detector. Theworking lumens (858, 859) preferably are sized to slidably interfacewith the outside of a sheath or guide instrument, such as thesheath/guide combination depicted in FIG. 193. The embodiment depictedin FIG. 194C also comprises another sheath instrument (818) and guideinstrument (819), the guide (819) defining a working lumen distalaperture (862) through which various tools may be positioned.

Referring to FIG. 194C, each of the sheath instruments (30, 818), guideinstruments (18, 819), and/or the larger endoscopic instrument (820) maycarry a localization sensor (864) or an ultrasound device (863), amongother things. Such instrumentation may be utilized to navigate,visualize, and coordinate the various instruments relative to each otherand surrounding structures.

FIGS. 194D, F, and G illustrate embodiments similar to that depicted inFIG. 194C, with the exception that more proximal aspects of theembodiments of FIGS. 194D, F, and G are depicted as well as the moredistal portions of such arrangements. Referring to FIG. 194D, aninstrument base (866) is depicted for the parent instrument (820) havingfour control element interface assemblies (132) configured forindependent interactions with four independent motors coupled thereto bya parent instrument driver (not shown) which is preferably similar tothat illustrated in reference to instrument driver (16) variationsabove. The four control element interface assemblies (132) preferablyare coupled to four independent tension elements (865) configured toomnidirectionally steer the preferably flexible parent instrument (820).In other variations, the parent instrument may have less than or morethan four tension elements—or none, in which case the parent instrumentis more similar to a conventional unsteerable endoscopic instrument. Asdepicted in the embodiment of FIG. 194D, a guide instrument (18) andsheath instrument (30) are positioned through a working lumen (858) ofthe parent instrument (820), and proximally, an instrument driver (16)for the guide (18) and sheath (30) instruments is depicted in aconfiguration similar to that described in reference to FIG. 502D. FIG.194G depicts an embodiment having two instrument set and driverconfigurations similar to that described in reference to FIG. 194D,while FIG. 194F depicts an embodiment having two instrument set anddriver configurations similar to that described in reference to FIG.194D, absent the electromechanical tool actuator (847). The instrumentdrivers for sheath/guide instruments, and larger parent instrument maybe coupled to an object such as an operating table, operating roomfloor, operating room ceiling, or other structure utilizing a supportstructure such as the fixed embodiments depicted (867, 868, 869) inFIGS. 194D, F, G, or support structure embodiments described above inreference to FIGS. 1, 2, and 3-3.10 b.

Combinations and permutations of the instrumentation described inreference to the embodiments in FIGS. 192-194 may be utilized formedical diagnosis and/or intervention throughout the body. In somescenarios, it is useful to have a separate real-time imaging modalitysuch as ultrasound, fluoroscopy, and/or optical or infrared cameracasting a field of view from a separate position relative to operationalinstruments such as those depicted in reference to the embodiments inFIGS. 192A-192Q.

For example, in an insufflated laparoscopy procedure, it may bepreferable to have an endoscope positioned near the umbilicus, and havean interventional tool, such as those embodiments depicted in FIGS.192A-192Q, positioned into the insufflated interventional theater, inthe field of view of the endoscope, from a different port. In otherembodiments, it is preferable to have real-time imaging componentscoupled to the instrument or instruments, in configurations similar tothose described in reference to FIG. 194. For example, in agastrointestinal procedure with limited interventional cavity space, itmay be preferable to have one or more imaging devices coupled to theoperational instruments, as in a configuration wherein a tool is withinthe field of view of the imaging device, and the tissue structuretargeted for intervention is in the background. In other scenarios, itmay be preferable to have both on-board imaging as well as remotelypositioned imaging.

Transvaginal Intervention:

Referring to FIG. 195A, a steerable guide (18) instrument and steerablesheath instrument (30) according to one embodiment maybe be coaxiallyadvanced transvaginally into the uterus (875). A tool (not shown), suchas one of those disclosed in FIGS. 192A-Q may be coaxially coupledwithin the guide (18). Referring to FIG. 195B, the guide and sheath maybe advanced as the assembly is also steered. Imaging modalities such asfluoroscopy, transcutaneous ultrasound, and instrument-mountedultrasound may be utilized to navigate the uterus (875). The vagina(876), uterus (875), fallopian tubes (872), and salpinx (874), may benavigated to access the ovaries (873) and peritoneum (887). The uterus(875) may be injected with saline or other fluid to facilitate imaging.Referring to FIG. 195C, for example, a saline-filled uterus (875) may beimaged with an ultrasound device (863) coupled to the guide instrument(30), such as a side firing ultrasound array, to observe tissue lesions(877) of interest. Referring to FIG. 195D, in another scenario theuterus (875) may be insufflated, and a steerable endoscopic instrumentassembly (820), such as that depicted in FIG. 194, may be advanced witha forward-looking image capture device (853), such as an optical imagingdevice. This may assist in locating the opening of a fallopian tube(872). Injection of saline, and atraumatic tissue manipulation using thedistal tip of the pertinent instrument may also assist in locating afallopian tube (872) opening, in addition to advanced imaging modalitiesas discussed herein. Referring to FIG. 195E, a sheath (30) and guide(18) are depicted steerably advancing toward a fallopian tube (872)opening.

Referring to FIG. 195F, the sheath (30) has been advanced just proximalof the opening of the fallopian tube (872), while the guide (18) hasbeen advanced into the fallopian tube (872). Such a configuration may beutilized to facilitate a falloposcopy procedure, a hystero-salpingogramwith contrast agent and fluoroscopy (in one embodiment, utilizing thesheath or an associated balloon to proximally occlude the fallopianwhile injecting contrast through the guide or another lumen (thusavoiding pressurizing the entire uterus with contrast as in aconventional procedure), or to remove an occlusion (879), such as atubal pregnancy, from a fallopian tube, as shown in FIGS. 196A-196C,where a grasper tool (802) is depicted positioned down the working lumenof a guide instrument, and is remotely actuated at aproximally-positioned instrument driver which may be manually orelectromechanically actuated, as described above. In one embodiment, aconfiguration such as that depicted in FIG. 194D with a grasper tool(802) such as that depicted in FIG. 192J may be utilized. In anotherembodiment, a configuration such as that depicted in FIG. 194D, butabsent the larger parent endoscopic instrument, may be utilized with agrasper tool (810) such as that depicted in FIG. 192J. Suction and/orinjection of saline or other fluid may also be utilized to facilitateclearance of an occlusion (879) with an apparatus such as that depictedin FIG. 195F.

Referring to FIG. 197A, the guide may comprise an expandable balloon(851) at its distal end, and the expandable balloon (851) may beutilized to place an expandable prosthesis (880), such as a stent orstent graft configured to either prevent occlusion or occlude (in thecase of a desired sterilization procedure) a fallopian tube (872). Asshown in FIG. 197B, subsequent to deployment of the expandableprosthesis (880), the expandable balloon (851) may be contracted, andthe guide (18) and sheath (30) retracted.

Referring to FIG. 198A, an ablation probe (881—RF, cryo, ultrasound,laser, etc) may be coupled to a guide (18) or positioned through theworking lumen of a guide (18), precisely positioned, and activated toproduce localized scarring (882) and intended occlusion of the fallopianfor sterilization, as depicted in FIG. 198B. Referring to FIG. 509A, agrasping (802) and/or cautery tool, such as a bipolar scissors orgraspers (not shown), may be utilized to remove extra tissue from thesalpinx (874) which may be preventing movement of eggs from an ovary(873) into an adjacent fallopian tube (872). FIG. 509B depicts the toolresecting away a piece of tissue (883). Extra tissue, characterized as“wispy”, is known to form at the salpinx (874) as a result of localizedinfection which may result from, for example, pelvic inflammatorydisease.

Referring to FIGS. 200A and 200B, a needle tool (816) according to oneembodiment may be directed to the ovary (873) with a steerable guide(18) and sheath (30) for a precise punch biopsy of the ovary. Similarly,a needle tool (816) may be utilized to drain cysts or ablate/lyseundesirable tissue.

Referring to FIGS. 201A-G, a robotic guide/sheath combination (18, 30)according to one embodiment may be utilized to minimally invasivelyconduct an oophorectomy. As shown in FIGS. 201A-C, a cutting and/orcautery tool, such as a scissors (814) or bipolar scissors, may beadvanced past the salpinx (874) to the location of the ovarian artery(884) where the ovarian artery may be cut and cauterized. Similarly, asdepicted in FIGS. 201D-E, the ovarian ligament (885) may be severedwhich a tool such as a scissors (814), after which a grasping tool (802)may be utilized to pull out the ovary (873), as depicted in FIG. 201F-G.

Referring to FIG. 202, a sheath (30) may be advanced past the salpinx(874) to facilitate further steerable advancement of the guide (18) andan associated tool into the peritoneum (887). This is significant inthat a steerable interventional assembly is depicted accessing theperitoneum (887) from a natural body orifice. The depicted guideconfiguration is coupled to an ultrasound device (863), such as aside-firing ultrasound array, and a retractable needle (886) alignedalong or within the field of view of the ultrasound device (863) to beable to image a targeted tissue portion along with the retractableneedle (886) in one image, a configuration which may be utilized forprecision image-guided biopsy, ablation (RF, cryo, laser, etc),injection (chemotherapy, gene/cell therapy, etc) and other activity asaccomplished with a distally-positioned tool, such as the depictedgrasper (802).

Referring to FIG. 203A-B, a steerable sheath alone maybe utilized toreposition and/or reorient a fallopian tube (872) to provide a preferredsetup angle/orientation/position for another coaxial device which may beadvanced through the sheath, past the salpinx, and into the peritoneum(887), to access targeted tissue lesions (877), as depicted in FIG.203C. From an intra-peritoneal position, many different interventionsmay be accomplished (stomach, bowel, pancreas, gall bladder, liver,etc), in addition to access to and intervention in the retro-peritonealspace (spleen, kidneys, large arteries) and pre-peritoneal space (herniarepair). For example, an ablation tool (RF, cryo, laser) or lysingneedle injection and/or ablation tool may be robotically driven intoposition and utilized to locate endometrial cells/lesions in theperitoneal space to lyse them and clinically minimize femaleendometriosis.

Laparoscopic Intervention:

Referring to FIGS. 514A-B, a laparoscopic salpingectomy employing oneembodiment is depicted for purposes of better understanding. A steerableendoscope comprising a guide (18) and sheath (30) instrument, and imagecapture device, is brought into an insufflated surgical theater (888)through an umbilicus port (889) and steered to produce a field of viewfacilitating operation of a steerable instrument assembly which maycomprise a cauterizing scissor or grasper, for example. Referring toFIGS. 203.5A-B, one or more instruments, such as additional sheath/guidepairings (818, 819), may be introduced through the umbilicus (889) orother ports (890) to access tissues located within the peritoneum,retroperitoneally, infraperitoneally, etc. Insufflation at approximately15 mm Hg and a Trendelenburg body position facilitates access andmaneuvering of laparoscopic tools. As shown in FIGS. 204A-B, a piece ofresected tissue (883) may be detached from the salpinx (874) and removedthrough the surgically created side port (890).

Many variations of port access may be utilized for laparoscopicprocedures with high-precision steerable tool assemblies such as thosedescribed herein. Preferred port access locations include but are notlimited to the umbilicus, and sub-bikini-line area. Insufflation at 15mmHg is typical, and may be administered through a lumen of one of theinstrument assemblies to produce a fairly large laparoscopic operationalprocedure. With a Trendelenburg patient orientation, the organs withinthe peritoneum are very accessible. As discussed above, visualizationmay comprise fluoroscopy, transcutaneous ultrasound, MR, and CT, butalso may include visualization from within the operational theater usingultrasound arrays and optical imaging devices carried upon theoperational instrument assemblies, as well as instrument assembliesspecifically included to carry imaging devices. In other words, imagingmay be carried along on an assembly with a tool assembly, or may befacilitated with one or more separate assemblies forcarrying/steering/driving the imaging devices within the operationaltheater.

Referring to FIGS. 204.5A-E, a laparoscopic oophorectomy procedure usinga robotic catheter system according to one embodiment is depicted. Incomparison to the procedure described in reference to FIGS. 201A-G, theprocedure depicted in FIGS. 204.5A-E is at least partially conductedthrough laparoscopic ports, such as through the umbilicus (889) and aside port (907), preferably located in the bikini line orsub-bikini-line area. As shown in FIG. 204.5A, a steerable endoscope,such as a parent instrument (820) described above, may be positionedthrough the umbilicus and steered remotely to provide the operator witha laparoscopic view of an ovary (873) and fallopian tube (872). Asteerable instrument, such as the sheath/guide combination (30, 18)depicted in FIG. 204.5A, may be maneuvered into a position from which atool, such as a scalpel (812), may be utilized along with other tools,such as cauterizing tools (806), to dissect the portion of the fallopiantube adjacent the salpinx (874), and also isolate the blood supply (884)and ligamentary support (885) of the subject ovary (873), to facilitateeasier removal from an endolumenal, trans-cervical pathway, as depictedin FIGS. 204.5D and 204.5E, with a grasper (802) or similar tool.

Referring to FIGS. 205A-B, a laparoscopic ovarian punch biopsy with aretractable needle tool (886) is depicted with access from a surgicallycreated side port (890). Optical imaging (not shown) may be facilitatedwith an umbilicus port and endoscope, an imaging device carried on thesheath/guide/tool assembly (30, 18), external imaging devices (fluoro,MR, CT, etc).

Referring to FIG. 206, a first sheath/guide/tool assembly (30, 18) isdepicted in the same insufflated laparoscopic interventional theater asa second instrument assembly, here comprising a steerable endoscopicinstrument (820) similar to that depicted in FIG. 194 with only a guideinstrument (819) coaxially associated therethrough (here without asheath instrument to demonstrate that a sheath instrument is not arequirement; indeed, suitable interventional assemblies may compriseonly a tool, a guide and tool, a tool/guide/sheath combination, aguide/endoscopic instrument combination, etc). The first instrumentassembly is depicted comprising a grasping tool (802) while the secondis depicted comprising an ablation (RF, cryo, laser, etc) tool (881).

Referring to FIG. 207A-B, a steerable endoscopic instrument (820) isoperated to keep the distal tip of an instrument assembly (18, 30) inthe field of view of the imaging device at the tip of the steerableendoscopic instrument (820). The instrument assembly comprises anablation tool (881) and is shown being driven around within theperitoneum to locate and ablate endometrial lesions (891).

Referring to FIG. 208A-D, according to one embodiment, two instrumentassemblies (896, 897) with needle grasping tools (802) may be utilizedlaparoscopically through two access ports (890, 892) to conduct acecopexy by suturing a portion of the cecum (895) against a portion ofthe abdominal wall (898), after which closed ports (909) are left toheal. In another embodiment (not shown), the two instrument assembliesmay be passed through lumens of the same steerable endoscopicinstrument, and passed into a laparoscopic operational theater through asingle larger port, as in configurations like those depicted in FIG.504. In another embodiment, as depicted in FIG. 208E, each of twoinstrument assemblies may be introduced into the laparoscopic operatingtheater from the side of the body (907, 904) opposite the cecum (895) toprovide the operator with more room within the body to maneuver andapproach the subject tissue. Two needle grasper instruments (802) aredepicted in FIG. 208E suturing a portion of the cecum (895) to a portionof adjacent abdominal wall tissue to conduct a cecopexy.

In any of the cecopexy embodiments discussed herein, depending upon theimaging modalities utilized, it may be preferable to also have anendoscope (not shown), such as an endoscope with a robotically steerableelectromechanical architecture as discussed herein, positioned throughthe umbilicus or other port to directly visualize the laparoscopicoperating theater. One or more cameras or scopes may also be positionedupon or adjacent to either instrument assembly, in a configuration, forexample, such as that depicted in FIG. 194.

Referring to FIGS. 209A-B, a laparoscopic appendectomy (893) is depictedutilizing three robotic steerable instrument assemblies (901, 902, 903)through three side ports (904, 890, 892) according to certainembodiments of the invention, one carrying an image capture device(853), and the other two carrying grasping, cutting, and/or cauterizingtools (802). Referring to FIGS. 209C-D, another embodiment is depictedwherein an endoscopic instrument (908) is positioned through theumbilicus (889) while two other tool assemblies (896, 897) areintroduced through side ports (904, 907) to grasp and remove theappendix (893) laparoscopically utilizing tools such as bipolarcauterizing scissors or graspers.

Referring to FIGS. 210A-H, one embodiment of a laparoscopicprostatectomy is depicted utilizing robotic instrument assembliesaccording to various embodiments of the invention. The umbilicus (889)and a variety of preferred laparoscopic surgical ports provide access tovarious facets of the male urinary system. Referring to FIG. 210A, theumbilicus (889) is a preferred port for a steerable endoscope (908) in alaparoscopic prostatectomy procedure given the pelvic anatomy andposition of other tissues. Referring to FIG. 210B, two other instrumentassemblies (902, 913) may be passed through bikini-line side ports toprovide direct access to the prostate gland (911). As shown in FIG.210C, a first instrument assembly (902) may comprise a grasping tool,while a second instrument assembly (913) may comprise a cutting tool,such as a bipolar scissors or scalpel. Referring to FIG. 210D, while oneinstrument assembly is utilized to dissect and manipulate the fascialtissue (914) around the prostate gland, the other instrument assemblymay be utilized to cut, grasp, cauterize, etc., until the prostate gland(911) is exposed. Referring to FIG. 210E, a grasping tool on oneinstrument assembly and a cutting tool on the other may be utilized todetach and dissect out the prostate (911) and prostatic urethra (912).Referring to FIG. 210F, the remaining urethra (912) ends may be repairedwith sutures (899). Referring to FIGS. 210G-H, the facial tissue (914)previously surrounding the prostate gland may be sutured (899) to itselfto form a collar about the urethra (912).

Referring to FIGS. 211A-C, two steerable instrument assemblies (902,915) according to certain embodiments of the invention may be utilizedto conduct a laparoscopic hemicolectomy, as facilitated by an imagecapture device positioned on a third instrument (907), as shown throughan umbilicus access port, or upon a instrument which is coupled to thetwo steerable instrument assemblies, as shown in FIG. 194. Referring toFIG. 211A, one instrument assembly may introduce a stapling orclip-applying tool (916) while another instrument assembly may introducea grasping, cutting, and/or cauterizing tool. Referring to FIG. 211B, aright hemicolectomy is conducted by stapling (917) off and isolating aportion of the right colon (900), then resecting and removing theisolated section, leaving two disconnected, stapled (917) ends.Referring to FIG. 211C, some or all of the staples may be removed whilethe discontinuity of the colon is addressed with additional staples orsutures to form an end-to-end anastomosis.

Referring to FIGS. 212A-C, one or more steerable instrument assembliesaccording to certain embodiments of the invention may be utilized toprecisely navigate the tissues of the pelvic region to place a slingprosthesis (919) around the neck of the urethra as it exits the femalebladder (910), to prevent prolapse of the bladder (910), urethra, orvagina (875). Appropriate suspension of the urethra may decreasesymptoms of female incontinence. Referring to FIG. 212C, the slingprosthesis (919) may be fastened anterior/superiorly to bones comprisingthe pelvis (920) or soft tissue structures, such as Cooper's ligament,as recommended by the manufacturers distributing such prosthesisproducts. Similarly, referring to FIGS. 523A-B, tensile suspensionelements (921), as simple as a single or multiple sutures, may beinstalled with steerable instrument assemblies and utilized to supportthe uterus (875) or urethral neck.

Referring to FIGS. 214A-C, a Heller myotomy may be conductedlaparoscopically by approaching a clinically overtight lower esophagealsphincter (924—“LES”) with a very high precision instrument assembly(923) according to one embodiment having a cutting or cauterizing tool(878), and surgically releasing (926) some of the muscle tissue thatcauses circumferential hoop stresses about the esophagus (925) at theLES (924). An image capture device (853) may be carried along on thesame or a separate instrument assembly (901, 908). The access route maybe from one or more surgically-created ports (901, 923), one of whichmay be the umbilicus (889). Referring to FIGS. 214D-E, a trans-thoracicapproach with higher port locations may also be utilized due to thelocation of the LES (924) between the thorax and abdomen.

Referring to FIGS. 215A-C, a Nissen fundoplication may be conductedlaparoscopically with two or more instrument assemblies (896, 903)configured to grasp the upper stomach (894) according to certainembodiments of the invention, create a folded around collar for the LESregion, and suture the collar into place, as depicted in FIG. 215C.Should the fundoplication produce an overly tight LES, one of thesutures (899) may be laparoscopically released to incrementally loosenthe hoop stress upon the LES created by the fundoplication. A similargroup of instruments (896, 903) may be utilized to create a Roux-en Yanastomosis (928), as shown in FIGS. 216A-C. Referring to FIG. 216D,along with a laparoscopic Roux-en Y anastomosis (928), a stomachreduction may be created with a series (929) of staples, sutures, and/orclips, installed from a robotic catheter platform such as thosedescribed herein. Alternatively, as depicted in FIG. 216E, a similarseries (930) of staples, sutures, and/or clips may be installed frominside of the stomach (894), utilizing an endolumenal fastening tool(916) and a steerable robotic catheter assembly such as those describedherein.

Urinary Intervention:

Referring to FIG. 217A, a steerable instrument assembly according to oneembodiment may be steered through the urethra (912) and into the bladder(910), where an image capture device (853) may be utilized, asfacilitated by injected saline, to conduct a cystoscopy and potentiallyobserve lesions (933) of interest. The omni-directional steerability andprecision of the robotic guide and/or sheath to which the image capturedevice is coupled facilitates collection of images of inside of thebladder (910) which may be patched together to form a 3-dimensionalimage. The instrument assembly (901) may also be utilized to advancetoward and zoom the image capture device upon any defects, such asobvious bleeds or tissue irregularities. Referring to FIG. 217B, theinstrument assembly (30, 18, 881) may alternatively or additionalcomprise an interventional tool such as an ablation tool (881) forablating tumors or other lesions (933) within the bladder (910).Referring to FIGS. 217C-D, a portion of the instrument assembly (forexample, a sheath distal tip may be positioned in the bladder at theentrance to the urethra while the more slender guide, 18, is driventoward and into the kidney, 932) may be advanced toward and steerablydriven into the kidney (932), where stones (936) may be captured withgraspers or other tools, or where stones may be destroyed usingchemistry, cryo, RF, or laser ablation tools (935), or other radiativetechniques, such as ultrasound, as depicted in FIGS. 217C-D.

Referring to FIG. 218A, the relatively elastic bladder (910) may beutilized as a flexible access point or setup/approach space forintraperitoneal structures such as the uterus (875), subsequent toadvancement past the urethra (912) and through the wall of the bladder(910) as shown in FIGS. 218A-C. As depicted in FIGS. 218B-C, this accessroute may be utilized for imaging/biopsy/lysing of tissue, ablation oftissue, injection of medication or cell/gene therapy, etc. within allareas of the uterus utilizing a slender tool, such as a retractableneedle (816) coupled to a steerable catheter platform (937). This accessroute may be utilized to navigate to, biopsy, mark, and/or lyse tissuelesions (938) such as fibroid tumors.

Upper Gastrointestinal Intervention:

From an endolumenal approach, the LES (924) may be dilated with aballoon (851) using steerable tool assemblies (30, 18) such as those inembodiments described herein. Referring to FIGS. 219A-C, a steerableinstrument assembly comprising an expandable balloon (851) may beprecisely located within the LES (924), expanded, and removed to atleast transiently dilate or expand the LES (924). Referring to FIGS.220A-C, an ablation tool (881) utilizing RF, laser, cryo, ultrasound,etc. may be coupled to a guide/sheath assembly (18, 30) and utilized toablate the tissue comprising an overly tight LES (924) from the insideto result in a dilated LES. Ablation may be combined with dilation, asin an expandable balloon with ablative properties. In one embodiment theablative tool (881) has circumferentially oriented ablation zones, asopposed to a discrete ablation zone at the distal tip of a conventionalRF ablation catheter, to apply a more dispersed ablation to the tissueof the surrounding LES (924) during a particular bout of ablativeaction.

Referring to FIGS. 221A-B, in one embodiment, an ablative probe tool(881) coupled to the end of a steerable instrument assembly (30, 18) maybe advanced and steered toward lesions of cells (939) known to producethe hormone “Ghrelin”, which activates specialized neurons in thehypothalamus involved in weight regulation. Ablation of a portion ofthese cells using RF, cryo, laser, ultrasound, etc may be used to treatobesity through appetite suppression.

Referring to FIGS. 222A-I, an elongate steerable instrument assembly(30, 18) may be utilized to navigate through the esophagus (925),through the stomach (894), and through the sphincter of Oddi (946) toaccess the pancreatic duct (941), common bile duct (945), cystic duct(943), gall bladder (940), hepatic ducts (944), and liver (942).Referring to FIG. 222B, one embodiment of a steerable instrumentassembly comprising a sheath instrument (30) and guide instrument (18)may be navigated into the duodenum, and the smaller guide instrument maybe turned and advanced through the sphincter of Oddi (946). Referring toFIG. 222C, the steerable guide (18) instrument may be navigated into thecommon bile duct (945) and up into the hepatic ducts (944) to clearobstructions, vacuum out stones (949, 936), and destroy stones (949,936), with energy and/or chemical treatments. Referring to FIG. 222D, asteerable guide instrument (18) comprising an ultrasound device (863),such as side-firing ultrasound array, and a retractable needle (886) maybe utilized to cannulate and clear obstructions within the cystic duct(943) and gall bladder (940). Referring to FIG. 222E, a steerable guideinstrument (18) may be utilized to deploy a self-expanding or expandableprosthesis (880), such as a stent or stent graft structure, within thesubject duct system, such as in the common bile duct (945). Referring toFIGS. 222F-G, an ablation or lithotripsy tool (948), such as thoseutilizing RF, cryo, ultrasound, and/or laser, may be utilized to clearobstructions, such as stones (949, 936), from the cystic duct (943)and/or gall bladder (940). Similarly, obstructions in the hepatic ductsystem may be addressed, as depicted in FIG. 222H.

As shown in FIG. 222I, subsequent to cannulating the sphincter of Oddi(946), rather than turning up the common bile duct (945), the steerableinstrument may be steered and advanced into the pancreatic duct (941),where it may be utilized to clear obstructions, such as stones, and maybe utilized to biopsy, treat, and/or lyse the pancreatic (947) tissueutilizing, for example, a side-firing ultrasound array with aside-protruding retractable needle configuration.

Referring to FIGS. 223A-G, a trans-gastric cholesectomy procedure usingone embodiment of the invention is depicted. Referring to FIGS. 223A-B,a steerable instrument, such as a sheath (30) and/or guide (18)instrument, is navigated to the right wall of the stomach (994), whichit is utilized to temporarily distend, as shown in FIG. 223B, a portionof the right stomach toward the gall bladder (940) to facilitateultrasound imaging of the structures adjacent the distal end of thesteerable instrument. The normal anatomic position of the gall bladder(940) and cystic duct (943) relative to the right stomach should createa beneficial field of view for ultrasound imaging, particularly with aportion of the stomach (894) distended over toward the region where thegall bladder (940) should be positioned. After confirming the locationof the gall bladder (940) and related structures, and also potentiallyrepositioning or re-vectoring the steerable instrument (30), a sterileportion of the instrument assembly is advanced across the gastric mucosatoward the cystic duct (943) and cystic artery (951), preferably alongwith an on-board image capturing means, to observe the distal end of theinstrument assembly, as depicted in FIG. 223D-F.

Referring to FIG. 223D, according to one embodiment, a clip applier (notshown) may be utilized to ligate the cystic duct (943), after which ascissors or other cutting tool (952) may be utilized to sever the cysticduct. A cautery/cutting tool, such as a bipolary cautery scissors (952),may be utilized to isolate the gall bladder (940) from the cystic artery(951), as depicted in FIG. 223E. Subsequently, as depicted in FIG. 223F,a dissection and/or cautery tool (952) may be utilized to dissect thegall bladder (940) away from the liver (942) bed. Another sterile tool(897) may be advanced across the gastric mucosa to grasp the gallbladder (940) and prevent spillage of its contents, as depicted in FIG.223F. Subsequent to separation of the gall bladder (940) from othertissue, it may be pulled through the gastric mucosa into the stomach(894) and removed through the mouth. The defect created in the gastricmucosa is closed (953) expediently using a suturing device or prostheticquick-connect port hardware, either of which may be coupled to thedistal end of a steerable instrument assembly for in-situ interventionas described herein. Transgastric access as described herein may also beutilized to access the peritoneum.

Lower Gastrointestinal Intervention:

Referring to FIGS. 224A-F, a steerable instrument assembly may beutilized to navigate past the rectum (955) and into the colon (900) andintervene to biopsy, lyse, and/or remove tissue defects or malformations(954), such as polyps. Referring to FIG. 224A, a steerable instrumentassembly (901) is depicted steerably navigating the colon (900) with aforward-looking image capture device (853), such as a CCD or fibercamera. The high degree of steerability of the instrument assemblyfacilitates examination of tissue defects (954) in all directions, asdepicted in FIG. 224B. Referring to FIG. 224C, the instrument assemblymay comprise multiple instrument sub-assemblies, one of which maycomprise a polyp-removing cautery snare device (957). As shown in FIGS.224D and 224E, the cautery snare device (957) may be precisely navigatedinto position, then utilized to cauterize and remove a tissue defect(954) such as a polyp. Referring to FIG. 224F, the instrument assemblymay then be redirected to another defect (954) where a similar processmay be repeated. Alternatively, a biopsy needle (not shown) may bedeployed from a steerable instrument assembly to precisely sample tissuedefects in the colon.

Trans-Bronchial Intervention:

Referring to FIGS. 225A-228D, one or more steerable instrumentassemblies may be utilized to navigate, diagnose, and treat the trachea(958), bronchii (959), and lungs (964). Referring to FIGS. 225A-C, asteerable instrument assembly (30, 18) comprising an expandable balloon(851) may be steerably advanced down the bronchi (959) and utilized todeploy an expandable prosthesis (960), such as a stent structure whichmay be configured to house a one-way valve, in the case of a treatmentfor a disease such as emphysema wherein it may be desirable to decreaseactive lung volume, a drug-eluting polymer, etc. In another embodiment,a stent may be deployed to assist in maintaining patency of a particularsection of airway. Referring to FIGS. 226A-D, certain bronchi (959) maybe ablated (881) with cryo, RF, ultrasound, etc to prevent constriction(961) of smooth muscle in the walls of the bronchi which may beassociated with asthma. The muscles themselves may be ablated (881), orthe motor neurons leading to them may be ablated, to leave the airwaysmore open (962).

Referring to FIGS. 227A-C, an ablation tool (881) may be coupled to asteerable instrument assembly (18, 30) to navigate the bronchi (959) andablate a specific location to cause a scarring (963) and eventualpartial or total occlusion of an airway leading to lung volume which isnot wanted, for reasons such as emphysema. Referring to FIGS. 228A-D, asteerable instrument may be utilized to position an ultrasound device(863), such as a side-firing ultrasound array, along with aside-protruding, retractable needle (866) which may also function as anelectrode, to find, biopsy, inject, ablate (886), and/or lyse potentialor known lesions (965), such as tumors, of the lung.

Arthroscopic Intervention:

Steerable tool assemblies according to some embodiments of the inventionmay be used to drive from side ports of a human knee synovial joint toposterior aspects of the same joint to facilitate precision passing of aneedle and suture from anterior or side to posterior and thereby repaira meniscus tear with sutures. A distracted synovial joint (such as thehip joint) may be investigated with a small steerable instrumentpositioned at the end of a slender steerable instrument assemblyconfigured to navigate a distracted and preferably irrigated jointspace, such as that of the human hip.

Spinal Intervention:

The steerable platform provided by embodiments of the invention may alsobe utilized to steer/navigate to the intervertebral disk space, e.g., bydriving around calcified tissue and nerves. A spinal tap may beconducted, and a very thin steerable device inserted and turned up theCSF channel into the subdural brain to vacuum out subdural hematomas,biopsy brain tissue, investigate, and otherwise navigate the brainregion.

Thoracic Intervention:

Steerable instruments and instrument assemblies according to someembodiments of the invention may also be utilized for IMA takedown andcauterization of associated small vessels after dropping one lung(preferably the left), then a bypass may be conducted with a distalanastomoses of one or more IMAs. A mediastinoscopy may be conducted froma suprasternal access route. The epicardial space may be accessed from asubxiphoid access route for epicardial ablation or pacing leadplacement. Lung wedge resection may be conducted from a transthoracicapproach, preferably utilizing CT/MR data to assist in guidance totissue defects such as tumors. Vagal nerve or splanchnic nerve pacingleads may be placed thoracoscopically with a high degree of precision.As described above, a Heller myotomy may be conducted from atrans-thoracic approach.

Nasopharynx Intervention:

As depicted in the embodiments of FIGS. 229A-F, the nasal/sinuspassageways may be navigated, diagnosed, and treated utilizing asteerable instrument assembly (30, 18) according to certain embodimentsof the invention. In one embodiment, the maxillary sinus may benavigated, irrigated, medicated with a steerable instrument having anoverall cross sectional dimension less than about 2.5 mm to pass throughthe nasal passageway (967) and past the entry to the maxillary sinus.Further, this entry to the maxillary sinus may be increased with a burr,drilling, or other dilation tool (966) configured to at least partiallyresect calcified and associated soft tissue with high degrees ofprecision, as depicted in FIG. 229G. In other embodiments, the frontal,ethmoidal, and sphenoidal sinuses may be accessed, diagnosed, andtreated.

Referring to FIG. 229A, each of the frontal, ethmoidal, sphenoidalsinuses may be access via the nasal passage, as well as the ostium tothe maxillary sinus. Referring to FIG. 229A, a steerable instrumentnavigates the ethmoidal spaces. Referring to FIG. 229C, a steerableinstrument navigates the frontal sinus. Referring to FIG. 229D, asteerable instrument navigates the sphenoidal sinus. Referring to FIG.229E, a steerable instrument is depicted entering the ostium into themaxillary sinus. Referring to FIG. 229F, the distal tip of the steerableinstrument is depicted navigating down into the maxillary sinus.Referring to FIG. 229G, a burr distal tip (966) is depicted which may beutilized for enlarging the ostium to the maxillary sinus.

Larnyx Intervention:

The larynx may be biopsied, modified, ablated, etc using theflexible/steerable platform provided by some embodiments, through themouth (968), in contrast to conventional rigid laryngoscopes. Referringto FIG. 230A, a steerable instrument assembly, preferably comprising animage capture device such as a direct visualization means, such as a CCDor fiber device, may be steerably and flexible navigated through themouth (968), and turned down into the region of the larynx (969).Referring to FIG. 230B, depending upon the particular anatomy of thepatient, significant turning and steerability may be required tonavigate the distal end of a steerable instrument assembly to thelarynx. FIGS. 230C-E depict various embodiments of tools which may becoupled to the distal end of a steerable instrument and utilized in thelarynx.

Referring to FIG. 230C, according to one embodiment, an ultrasounddevice (863), such as a side firing ultrasound array, with a sideprotruding retractable needle (886) is depicted. The needle (886) may beconfigured to function as an ablation electrode in one embodiment. Theultrasound device (863) may be utilized to guide the needle intoposition within, against, or adjacent to a targeted tissue mass, such asa suspected tumor. The retractable needle may be utilized to biopsy,ablate (RF, cryo, laser, ultrasound, etc), lyse, inject, etc thetargeted tissue mass. Referring to FIG. 230D, a more bluntly-shapedablation tip (881) may optionally be utilized to ablate (RF, cryo,laser, etc) or lyse a targeted tissue mass, and potentially cause thetargeted tissue mass (970) to scar down or shrink. Referring to FIG.230E, a grasper (802) or other tool may be utilized to surgicallyintervene in the larynx (969) area to place a prosthesis, remove a massor obstruction, or surgically modify targeted tissue to address clinicalproblems such as sleep apnea.

Thyroid/Parathyroid Intervention:

Referring to FIGS. 231A-C, one or more steerable instrument assembliesaccording to various embodiments may be navigated from a transcutaneousaccess point above the clavicle, to the region of the thyroid (971) andparathyroid (972). Once in the area of the thyroid (971), the steerableinstruments (896, 820/901), preferably comprising an image capturedevice such as a direct visualization means such as a CCD or fiberdevice, may be utilized to examine the thyroid (971) and/or parathyroid(972), biopsy them, ablate them (RF, cryo, laser, ultrasound, etc)partially lyse them, inject them, or resect and remove a portion ofeither of them. Referring to FIG. 231A, with a forward-looking steerableendoscope (820, 901) focused upon the thyroid and/or parathyroid, one ormore steerable instrument assemblies (896) constructed according to someembodiments, may be utilized to manipulate the thyroid and/orparathyroid. In one embodiment, a grasping and resection tool (802),such as a bipolar grasper or scissor, may be utilized to resect portionsof the thyroid and/or parathyroid. Referring to FIG. 231B, an ablationtool (881—RF, cryo, laser, ultrasound, etc) may be utilized to destroy aportion of the thyroid and/or parathyroid in situ. Referring to FIG.231C, should one or more of the nodes of the parathyroid (972) beun-locatable in the normal position adjacent the thyroid (971), thesteerable instruments may be backed off and steered down into themediastinal region (973) in hopes of locating the missing nodes of theparathyroid (972) in such location.

Vascular Intervention:

Expandable prostheses, such as stents and stentgrafts, may be deployedand locked into place with decreased risk of “endoleaks” by deployingsmall nitinol or stainless toggle bolt type staple clips tackedcircumferentially around, and longitudinally down the long axis of, astent or stent-graft from the inside out using the subject steerableinstrument system of various embodiments of the invention. Referring toFIGS. 232A-C, the subject steerable instrument platform may be utilizedthroughout the ascending aorta to navigate, diagnose, treat, andintervene with distally-deployed tools such as clip or staple appliers,retractable needles, etc. Referring to FIG. 232A, a steerable guide (18)and sheath (30) assembly navigates the renal artery (975). Referring toFIG. 232B, a steerable instrument navigates the celiac trunk (977).Referring to FIG. 232C, a steerable instrument navigates the aortic arch(976) and may be utilized to enter the left ventricle of the heart (974)from a retrograde approach through the aortic outflow tract.

Referring to FIGS. 233A-E, renal artery (975) interventions aredepicted. Referring to FIG. 233A, an expandable or self-expandingprosthesis (979), such as a stent or stent graft, may be deployed froman embodiment of the steerable instrument assembly, such as thatdepicted. The depicted instrument assembly may comprise an expandableballoon (851) and be observed in part with fluoroscopy. Referring toFIG. 233B, in another embodiment, a similar instrument assembly may beutilized to dilate a renal artery (975) lumen. Referring to FIG. 233C, agrasping (802) or cutting tool may be utilized to clear an obstruction(980) in the renal artery to ensure adequate perfusion of the kidneys(932). Referring to FIG. 233D, an ablation tool (881) distally carriedby the guide instrument (18) may be utilized to ablate (RF, cryo, laser,ultrasound, etc) plaques or other obstructions (980) in the renalartery. Referring to FIG. 233E, a steerable instrument platform may beutilized to ablate (881) tissue lesions within the kidney (982)parenchyma, or deliver radioactive seeds to lesions within theparenchyma of the kidney (982) from a transvascular approach.Fluoroscopy may be utilized to observe placement of such seeds or otherprostheses.

Referring to FIGS. 234A-E, a downsized steerable instrument assemblyaccording to one embodiment may be navigated up into the carotid artery(983), and more particularly, may be utilized to navigate around plaquesand other potentially unstable zones or structures (984), utilizingmodern imaging modalities, such as CT and MR, along with the navigationcapabilities of the subject system, to plan a path around key obstaclesand electromechanically execute on such plan. For example, referring toFIGS. 234A-234E, a distal protection device (985) may be carefullydeployed from a fairly distal position achieved by a steerableinstrument platform (30, 18). Subsequently, as depicted in FIGS. 234C-D,ablation (881), obliteration, or plaque removal by RF, ultrasound,vacuum, grasper, cryo, laser, etc may be conducted with the distalprotection device (985) safely in place. Later, as depicted in FIG.234E, the distal protection device (985) may be retrieved.

Referring to FIGS. 235A-D, a downsized steerable instrument assembly(18, 30) according to another embodiment may be utilized to navigatepast the carotid arteries and up into the peripheral neurovascular, allthe way to the circle of Willis. Suction tools may be utilized toretrieve clots, aneurysm-filling devices, such as coils, may be placedwith a high degree of precision, and brain tissue may be biopsied,ablated (RF, cryo, laser, ultrasound), injected, etc, among otherthings.

Other Interventions—Saphenous Vein Harvesting, Plastic Surgery:

The steerable instruments provided by embodiments of the invention canprovide the equivalent of a Guidant “VasoView” procedure for harvestingthe Saphenous vein, but significantly improved—because of thesteerability of the subject instruments (they can make sharp turnsimmediately after a transcutaneous crossing—unlike the stiff, straightVasoView).

By way of non-limiting example, face lift dissection may be accomplishedfrom behind the ears with this highly steerable platform configured tosteer with precision around convex surfaces, such as the transcutaneousface. Similarly, the steerability of the subject platform may beutilized to facilitate liposuction of the front, side, and posteriorpelvic region from one or more bikini area transcutaneous access ports,as well as breast implant dissection and placement from an umbilicusaccess port, and brow lift subcutaneous dissection from a more posteriorposition (back away from the hairline where the port or ports will beless visible subsequent to the intervention).

What is claimed is:
 1. A robotic medical system, comprising: an elongateflexible sheath instrument comprising a sheath instrument base and asheath instrument lumen; an elongate flexible guide instrumentpositioned in the sheath instrument lumen, the guide instrumentcomprising a guide instrument base and a guide instrument lumen; aninstrument driver having a sheath instrument interface and a guideinstrument interface, wherein the sheath instrument base may beoperatively and removably coupled to the sheath instrument interface,such that movement of the sheath instrument may be roboticallycontrolled by the instrument driver via the sheath instrument interface,wherein the guide instrument base may be operatively and removablycoupled to the guide instrument interface, such that movement of theguide instrument may be robotically controlled by the instrument drivervia the guide instrument interface, and wherein the sheath instrumentinterface and guide instrument interface are independently translatablerelative to one another, such that the sheath instrument and guideinstrument are axially translatable relative to the sheath instrument;and an elongate guidewire positioned in the guide instrument lumen, theguidewire having a proximal end coupled to an actuator, the actuatorbeing removably coupled to the instrument driver, wherein movement ofthe guidewire may be robotically controlled by the actuator.
 2. Therobotic medical system of claim 1, wherein the actuator is anelectro-mechanical actuator.
 3. The robotic medical system of claim 1,wherein a distal end of the guidewire may be extended out of, andretracted back into, a distal opening of the guide instrument.
 4. Therobotic medical system of claim 1, wherein the guidewire may becontrolled in two degrees of freedom.
 5. The robotic medical system ofclaim 4, wherein the two degrees of freedom includes rolling theguidewire.
 6. The robotic medical system of claim 4, wherein the twodegrees of freedom includes bending the guidewire.
 7. A robotic medicalsystem, comprising: a master input device; an instrument driver; aflexible sheath instrument comprising a sheath instrument base removablycoupled to the instrument driver, the sheath instrument defining asheath instrument working lumen; a flexible guide instrument comprisinga guide instrument base removably coupled to the instrument driver, theguide instrument positioned in the sheath instrument working lumen anddefining a guide instrument working lumen; and an elongate guidewirepositioned in the guide instrument lumen, and having a proximal endcoupled to a guidewire actuator that is removably and operativelycoupled to the instrument driver, such that each of said sheathinstrument, guide instrument, and guidewire are independentlycontrollable by the instrument driver in response to user commandsentered through the master input device.
 8. The robotic medical systemof claim 7, wherein the actuator is an electro-mechanical actuator. 9.The robotic medical system of claim 7, wherein a distal end of theguidewire may be extended out of, and retracted back into, a distalopening of the guide instrument.
 10. The robotic medical system of claim7, wherein the actuator is configured to control the guidewire in twodegrees of freedom.
 11. The robotic medical system of claim 10, whereinthe two degrees of freedom includes rolling the guidewire.
 12. Therobotic medical system of claim 10, wherein the two degrees of freedomincludes bending the guidewire.